Remove unneeded `extern crate`s

Closes GH-28.

Co-authored-by: Bernhard Berger <[e-mail]>

Untitled.txt

···
 ```rs
 // ---------------------
 // Useful helper:
-extern crate std;
 use std::println;
 use alloc::string::String;
 

benches/bench.rs

···
-#[macro_use]
-extern crate criterion;
-use criterion::{BenchmarkId, Criterion};
+use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use std::fs;
 
 fn readme(c: &mut Criterion) {

build.rs

···
-extern crate reqwest;
 use regex::Regex;
 use std::fs;
 
···
 // > 👉 **Important**: this module is generated by `build.rs`.
 // > It is generate from the latest CommonMark website.
 
-extern crate markdown;
 use markdown::{{to_html_with_options, CompileOptions, Options}};
 use pretty_assertions::assert_eq;
 

examples/lib.rs

···
-extern crate markdown;
-
 fn main() -> Result<(), String> {
     // Turn on debugging.
     // You can show it with `RUST_LOG=debug cargo run --example lib`

fuzz/fuzz_targets/markdown.rs

···
 #![no_main]
 use libfuzzer_sys::fuzz_target;
-extern crate markdown;
 
 fuzz_target!(|data: &[u8]| {
     if let Ok(s) = std::str::from_utf8(data) {
         let _ = markdown::to_html(s);
-        let _ = markdown::to_html_with_options(
-            s,
-            &markdown::Options::gfm()
-        );
+        let _ = markdown::to_html_with_options(s, &markdown::Options::gfm());
         let _ = markdown::to_mdast(s, &markdown::ParseOptions::default());
         let _ = markdown::to_mdast(s, &markdown::ParseOptions::gfm());
     }

readme.md

···
 ## Use
 
 ```rs
-extern crate markdown;
-
 fn main() {
     println!("{}", markdown::to_html("## Hello, *world*!"));
 }
···
 Extensions (in this case GFM):
 
 ```rs
-extern crate markdown;
-
 fn main() -> Result<(), String> {
     println!(
         "{}",
···
 Syntax tree ([mdast][]):
 
 ```rs
-extern crate markdown;
-
 fn main() -> Result<(), String> {
     println!(
         "{:?}",

src/configuration.rs

···
 
 #[cfg(test)]
 mod tests {
-    extern crate std;
     use super::*;
     use crate::util::mdx::Signal;
     use alloc::format;

src/util/line_ending.rs

···
-extern crate alloc;
-
 use alloc::{str::FromStr, string::String};
 
 /// Type of line endings in markdown.
···
 
 #[cfg(test)]
 mod tests {
-    extern crate std;
     use super::*;
 
     #[test]

src/util/mdx.rs

···
-extern crate alloc;
-
 use alloc::string::String;
 
 /// Signal used as feedback when parsing MDX ESM/expressions.
···
 
 #[cfg(test)]
 mod tests {
-    extern crate std;
     use super::*;
     use alloc::boxed::Box;
 

tests/attention.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Emphasis, Node, Paragraph, Root, Strong, Text},
     to_html, to_html_with_options, to_mdast,

tests/autolink.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Link, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/block_quote.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{BlockQuote, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/character_escape.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/character_reference.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/code_fenced.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Code, Node, Root},
     to_html, to_html_with_options, to_mdast,

tests/code_indented.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Code, Node, Root},
     to_html, to_html_with_options, to_mdast,

tests/code_text.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{InlineCode, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/commonmark.rs

···
 // > 👉 **Important**: this module is generated by `build.rs`.
 // > It is generate from the latest CommonMark website.
 
-extern crate markdown;
 use markdown::{to_html_with_options, CompileOptions, Options};
 use pretty_assertions::assert_eq;
 

tests/definition.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Definition, Node, Root},
     to_html, to_html_with_options, to_mdast,

tests/frontmatter.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Node, Root, Toml, Yaml},
     to_html, to_html_with_options, to_mdast,

tests/fuzz.rs

···
-extern crate markdown;
 use markdown::{mdast, to_html, to_html_with_options, to_mdast, Options};
 use pretty_assertions::assert_eq;
 

tests/gfm_autolink_literal.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Link, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/gfm_footnote.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{FootnoteDefinition, FootnoteReference, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/gfm_strikethrough.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Delete, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/gfm_table.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{AlignKind, InlineCode, Node, Root, Table, TableCell, TableRow, Text},
     to_html, to_html_with_options, to_mdast,

tests/gfm_tagfilter.rs

···
-extern crate markdown;
 use markdown::{to_html_with_options, CompileOptions, Options};
 use pretty_assertions::assert_eq;
 

tests/gfm_task_list_item.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{List, ListItem, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/hard_break_escape.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Break, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/hard_break_trailing.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Break, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/heading_atx.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Heading, Node, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/heading_setext.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Heading, Node, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/html_flow.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Html, Node, Root},
     to_html, to_html_with_options, to_mdast,

tests/html_text.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Html, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/image.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Definition, Image, ImageReference, Node, Paragraph, ReferenceKind, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/link_reference.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Definition, LinkReference, Node, Paragraph, ReferenceKind, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/link_resource.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Link, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/list.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{List, ListItem, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/math_flow.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Math, Node, Root},
     to_html, to_html_with_options, to_mdast,

tests/math_text.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{InlineMath, Node, Paragraph, Root, Text},
     to_html, to_html_with_options, to_mdast,

tests/mdx_esm.rs

···
-extern crate markdown;
 mod test_utils;
 use markdown::{
     mdast::{MdxjsEsm, Node, Root},

tests/mdx_expression_flow.rs

···
-extern crate markdown;
 mod test_utils;
 use markdown::{
     mdast::{MdxFlowExpression, Node, Root},

tests/mdx_expression_text.rs

···
-extern crate markdown;
 mod test_utils;
 use markdown::{
     mdast::{MdxTextExpression, Node, Paragraph, Root, Text},

tests/mdx_jsx_flow.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{List, ListItem, MdxJsxFlowElement, Node, Paragraph, Root, Text},
     to_html_with_options, to_mdast,

tests/mdx_jsx_text.rs

···
-extern crate markdown;
 mod test_utils;
 use markdown::{
     mdast::{

tests/mdx_swc.rs

···
-extern crate markdown;
 mod test_utils;
 use markdown::{to_html_with_options, Constructs, Options, ParseOptions};
 use pretty_assertions::assert_eq;

tests/misc_bom.rs

···
-extern crate markdown;
 use markdown::to_html;
 use pretty_assertions::assert_eq;
 

tests/misc_dangerous_html.rs

···
-extern crate markdown;
 use markdown::{to_html, to_html_with_options, CompileOptions, Options};
 use pretty_assertions::assert_eq;
 

tests/misc_dangerous_protocol.rs

···
-extern crate markdown;
 use markdown::to_html;
 use pretty_assertions::assert_eq;
 

tests/misc_default_line_ending.rs

···
-extern crate markdown;
 use markdown::{to_html, to_html_with_options, CompileOptions, LineEnding, Options};
 use pretty_assertions::assert_eq;
 

tests/misc_line_ending.rs

···
-extern crate markdown;
 use markdown::{to_html, to_html_with_options, CompileOptions, Options};
 use pretty_assertions::assert_eq;
 

tests/misc_soft_break.rs

···
-extern crate markdown;
 use markdown::to_html;
 use pretty_assertions::assert_eq;
 

tests/misc_tabs.rs

···
-extern crate markdown;
 use markdown::{to_html, to_html_with_options, CompileOptions, Options};
 use pretty_assertions::assert_eq;
 

tests/misc_url.rs

···
-extern crate markdown;
 use markdown::to_html;
 use pretty_assertions::assert_eq;
 

tests/misc_zero.rs

···
-extern crate markdown;
 use markdown::to_html;
 use pretty_assertions::assert_eq;
 

tests/test_utils/hast.rs

···
 // ^-- To do: externalize.
 
 extern crate alloc;
-extern crate markdown;
 use alloc::{
     fmt,
     string::{String, ToString},

tests/test_utils/hast_util_to_swc.rs

···
 //! TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 //! SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-extern crate swc_common;
-extern crate swc_ecma_ast;
 use crate::test_utils::{
     hast,
     swc::{parse_esm_to_tree, parse_expression_to_tree},

tests/test_utils/mdx_plugin_recma_document.rs

···
 //! Port of <https://github.com/mdx-js/mdx/blob/main/packages/mdx/lib/plugin/recma-document.js>,
 //! by the same author.
 
-extern crate swc_ecma_ast;
 use crate::test_utils::{
     hast_util_to_swc::Program,
     swc_utils::{bytepos_to_point, prefix_error_with_point, span_to_position},

tests/test_utils/mdx_plugin_recma_jsx_rewrite.rs

···
 //! Port of <https://github.com/mdx-js/mdx/blob/main/packages/mdx/lib/plugin/recma-jsx-rewrite.js>,
 //! by the same author.
 
-extern crate swc_common;
-extern crate swc_ecma_ast;
 use crate::test_utils::{
     hast_util_to_swc::Program,
     swc_utils::{

tests/test_utils/swc.rs

···
 //! Bridge between `markdown-rs` and SWC.
-extern crate markdown;
-extern crate swc_common;
-extern crate swc_ecma_ast;
-extern crate swc_ecma_parser;
+
 use crate::test_utils::swc_utils::{bytepos_to_point, prefix_error_with_point, RewriteContext};
 use markdown::{mdast::Stop, unist::Point, Location, MdxExpressionKind, MdxSignal};
 use swc_common::{

tests/text.rs

···
-extern crate markdown;
 use markdown::to_html;
 use pretty_assertions::assert_eq;
 

tests/thematic_break.rs

···
-extern crate markdown;
 use markdown::{
     mdast::{Node, Root, ThematicBreak},
     to_html, to_html_with_options, to_mdast,

tests/xxx_hast_util_to_swc.rs

···
-extern crate markdown;
-extern crate swc_common;
-extern crate swc_ecma_ast;
-extern crate swc_ecma_codegen;
 mod test_utils;
 use pretty_assertions::assert_eq;
 use test_utils::{

tests/xxx_mdast_util_to_hast.rs

···
-extern crate markdown;
 mod test_utils;
 use markdown::mdast;
 use pretty_assertions::assert_eq;

tests/xxx_mdx.rs

···
-extern crate markdown;
-extern crate swc_common;
-extern crate swc_ecma_ast;
-extern crate swc_ecma_codegen;
 mod test_utils;
 use pretty_assertions::assert_eq;
 use test_utils::mdx::{mdx, JsxRuntime, Options};

tests/xxx_mdx_plugin_recma_document.rs

···
-extern crate markdown;
-extern crate swc_common;
-extern crate swc_ecma_ast;
-extern crate swc_ecma_codegen;
 mod test_utils;
 use markdown::{to_mdast, Location, ParseOptions};
 use pretty_assertions::assert_eq;

tests/xxx_mdx_plugin_recma_jsx_rewrite.rs

···
-extern crate markdown;
-extern crate swc_common;
-extern crate swc_ecma_ast;
-extern crate swc_ecma_codegen;
 mod test_utils;
 use markdown::{to_mdast, Location, ParseOptions};
 use pretty_assertions::assert_eq;