move all lib code into internal

README.md

···
 
 ### As CLI tool
 ```bash
-gleam run -m run ./examples/helloworld.bf
+gleam run -m gbf/run ./examples/helloworld.bf
 #> Hello World!
 ```

src/gbf.gleam

···
 import ascii
-import gbf/eval
-import gbf/lexer
-import gbf/parser
-import gbf/vm.{type VirtualMachine}
+import gbf/internal/eval
+import gbf/internal/lexer
+import gbf/internal/parser
+import gbf/internal/vm.{type VirtualMachine}
 import gleam/list
 import gleam/result
 import gleam/string

src/gbf/eval.gleam src/gbf/internal/eval.gleam

···
-import gbf/lexer
-import gbf/parser.{type AST, type Block, type Command}
-import gbf/token
-import gbf/vm.{type VirtualMachine}
+import gbf/internal/lexer
+import gbf/internal/parser.{type AST, type Block, type Command}
+import gbf/internal/token
+import gbf/internal/vm.{type VirtualMachine}
 import gleam/int
 import gleam/list
 import gleam/result

src/gbf/lexer.gleam src/gbf/internal/lexer.gleam

···
-import gbf/token.{type Token}
+import gbf/internal/token.{type Token}
 import gleam/list
 import gleam/string
 import splitter

src/gbf/parser.gleam src/gbf/internal/parser.gleam

···
-import gbf/lexer.{type Position, Position}
-import gbf/token.{type Token}
+import gbf/internal/lexer.{type Position, Position}
+import gbf/internal/token.{type Token}
 import gleam/list
 import gleam/pair
 import gleam/result

test/gbf_lexer_test.gleam

···
-import gbf/lexer
-import gbf/token
+import gbf/internal/lexer
+import gbf/internal/token
 import gleeunit/should
 
 pub fn can_lex_test() {

test/gbf_parser_test.gleam

···
-import gbf/lexer.{Position}
-import gbf/parser.{Block, Leaf, Node}
-import gbf/token.{DecrementByte, IncrementByte, IncrementPointer}
+import gbf/internal/lexer.{Position}
+import gbf/internal/parser.{Block, Leaf, Node}
+import gbf/internal/token.{DecrementByte, IncrementByte, IncrementPointer}
 import gleeunit/should
 
 pub fn should_parse_test() {

test/gbf_test.gleam

···
 import gbf
-import gbf/vm
 import gleeunit
 import gleeunit/should
 
···
   let assert Ok(bvm) = gbf.run(input)
 
   bvm
-  |> vm.output
+  |> gbf.output
   |> should.equal("Hello World!\n")
 }

test/gbf_vm_test.gleam

···
 import ascii
-import gbf/vm.{type VirtualMachine}
+import gbf/internal/vm.{type VirtualMachine}
 import gleam/result
 import gleeunit/should