Nix docs: remove `with lib;` from example code

Following [Best Practices](https://nix.dev/guides/best-practices#with-scopes),
`with` is a problematic language construction and should be avoided.

Usually it is employed like a "factorization": `[ X.A X.B X.C X.D ]` is written
`with X; [ A B C D ]`.

However, as shown in the link above, the syntatical rules of `with` are not so
intuitive, and this "distributive rule" is very selective, in the sense that
`with X; [ A B C D ]` is not equivalent to `[ X.A X.B X.C X.D ]`.

However, this factorization is still useful to "squeeze" some code, especially
in lists like `meta.maintainers`.

On the other hand, it becomes less justifiable in bigger scopes. This is
especially true in cases like `with lib;` in the top of expression and in sets
like `meta = with lib; { . . . }`.

That being said, this patch removes most of example code in the current
documentation.

The exceptions are, for now
- doc/functions/generators.section.md
- doc/languages-frameworks/coq.section.md

because, well, they are way more complicated, and I couldn't parse them
mentally - yet another reason why `with` should be avoided!

doc/languages-frameworks/dotnet.section.md

···
 
   nugetSha256 = "sha256-ZG2HFyKYhVNVYd2kRlkbAjZJq88OADe3yjxmLuxXDUo=";
 
-  meta = with lib; {
+  meta = {
     homepage = "https://cmd.petabridge.com/index.html";
     changelog = "https://cmd.petabridge.com/articles/RELEASE_NOTES.html";
-    license = licenses.unfree;
-    platforms = platforms.linux;
+    license = lib.licenses.unfree;
+    platforms = lib.platforms.linux;
   };
 }
 ```

doc/languages-frameworks/go.section.md

···
 
   vendorHash = "sha256-ciBIR+a1oaYH+H1PcC8cD8ncfJczk1IiJ8iYNM+R6aA=";
 
-  meta = with lib; {
+  meta = {
     description = "Simple command-line snippet manager, written in Go";
     homepage = "https://github.com/knqyf263/pet";
-    license = licenses.mit;
-    maintainers = with maintainers; [ kalbasit ];
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ kalbasit ];
   };
 }
 ```

doc/languages-frameworks/idris.section.md

···
     hash = "sha256-h28F9EEPuvab6zrfeE+0k1XGQJGwINnsJEG8yjWIl7w=";
   };
 
-  meta = with lib; {
+  meta = {
     description = "Idris YAML lib";
     homepage = "https://github.com/Heather/Idris.Yaml";
-    license = licenses.mit;
-    maintainers = [ maintainers.brainrape ];
+    license = lib.licenses.mit;
+    maintainers = [ lib.maintainers.brainrape ];
   };
 }
 ```

doc/languages-frameworks/javascript.section.md

···
 
   NODE_OPTIONS = "--openssl-legacy-provider";
 
-  meta = with lib; {
+  meta = {
     description = "A modern web UI for various torrent clients with a Node.js backend and React frontend";
     homepage = "https://flood.js.org";
-    license = licenses.gpl3Only;
-    maintainers = with maintainers; [ winter ];
+    license = lib.licenses.gpl3Only;
+    maintainers = with lib.maintainers; [ winter ];
   };
 }
 ```

doc/languages-frameworks/lua.section.md

···
   disabled = (luaOlder "5.1") || (luaAtLeast "5.4");
   propagatedBuildInputs = [ bit32 lua std_normalize ];
 
-  meta = with lib; {
+  meta = {
     homepage = "https://github.com/luaposix/luaposix/";
     description = "Lua bindings for POSIX";
-    maintainers = with maintainers; [ vyp lblasc ];
+    maintainers = with lib.maintainers; [ vyp lblasc ];
     license.fullName = "MIT/X11";
   };
 };

doc/languages-frameworks/maven.section.md

···
       --add-flags "-jar $out/share/jd-cli/jd-cli.jar"
   '';
 
-  meta = with lib; {
+  meta = {
     description = "Simple command line wrapper around JD Core Java Decompiler project";
     homepage = "https://github.com/intoolswetrust/jd-cli";
-    license = licenses.gpl3Plus;
-    maintainers = with maintainers; [ majiir ];
+    license = lib.licenses.gpl3Plus;
+    maintainers = with lib.maintainers; [ majiir ];
   };
 }:
 ```

doc/languages-frameworks/ocaml.section.md

···
     hash = "sha256-d5/3KUBAWRj8tntr4RkJ74KWW7wvn/B/m1nx0npnzyc=";
   };
 
-  meta = with lib; {
+  meta = {
     homepage = "https://github.com/flowtype/ocaml-wtf8";
     description = "WTF-8 is a superset of UTF-8 that allows unpaired surrogates.";
-    license = licenses.mit;
-    maintainers = [ maintainers.eqyiel ];
+    license = lib.licenses.mit;
+    maintainers = [ lib.maintainers.eqyiel ];
   };
 }
 ```

doc/languages-frameworks/python.section.md

···
     hypothesis
   ];
 
-  meta = with lib; {
+  meta = {
     changelog = "https://github.com/pytest-dev/pytest/releases/tag/${version}";
     description = "Framework for writing tests";
     homepage = "https://github.com/pytest-dev/pytest";
-    license = licenses.mit;
-    maintainers = with maintainers; [ domenkozar lovek323 madjar lsix ];
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ domenkozar lovek323 madjar lsix ];
   };
 }
 ```
···
     python-daemon
   ];
 
-  meta = with lib; {
+  meta = {
     # ...
   };
 }
···
     "toolz.dicttoolz"
   ];
 
-  meta = with lib; {
+  meta = {
     changelog = "https://github.com/pytoolz/toolz/releases/tag/${version}";
     homepage = "https://github.com/pytoolz/toolz";
     description = "List processing tools and functional utilities";
-    license = licenses.bsd3;
-    maintainers = with maintainers; [ fridh ];
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [ fridh ];
   };
 }
 ```
···
     pytest
   ];
 
-  meta = with lib; {
+  meta = {
     changelog = "https://github.com/blaze/datashape/releases/tag/${version}";
     homepage = "https://github.com/ContinuumIO/datashape";
     description = "A data description language";
-    license = licenses.bsd2;
-    maintainers = with maintainers; [ fridh ];
+    license = lib.licenses.bsd2;
+    maintainers = with lib.maintainers; [ fridh ];
   };
 }
 ```
···
     libxslt
   ];
 
-  meta = with lib; {
+  meta = {
     changelog = "https://github.com/lxml/lxml/releases/tag/lxml-${version}";
     description = "Pythonic binding for the libxml2 and libxslt libraries";
     homepage = "https://lxml.de";
-    license = licenses.bsd3;
-    maintainers = with maintainers; [ sjourdois ];
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [ sjourdois ];
   };
 }
 ```
···
   # Tests cannot import pyfftw. pyfftw works fine though.
   doCheck = false;
 
-  meta = with lib; {
+  meta = {
     changelog = "https://github.com/pyFFTW/pyFFTW/releases/tag/v${version}";
     description = "A pythonic wrapper around FFTW, the FFT library, presenting a unified interface for all the supported transforms";
     homepage = "http://hgomersall.github.com/pyFFTW";
-    license = with licenses; [ bsd2 bsd3 ];
-    maintainers = with maintainers; [ fridh ];
+    license = with lib.licenses; [ bsd2 bsd3 ];
+    maintainers = with lib.maintainers; [ fridh ];
   };
 }
 ```
···
     wheel
   ];
 
-  meta = with lib; {
+  meta = {
     changelog = "https://github.com/pytoolz/toolz/releases/tag/${version}";
     homepage = "https://github.com/pytoolz/toolz/";
     description = "List processing tools and functional utilities";
-    license = licenses.bsd3;
-    maintainers = with maintainers; [ fridh ];
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [ fridh ];
   };
 }
 ```

doc/languages-frameworks/rust.section.md

···
 
   cargoHash = "sha256-jtBw4ahSl88L0iuCXxQgZVm1EcboWRJMNtjxLVTtzts=";
 
-  meta = with lib; {
+  meta = {
     description = "A fast line-oriented regex search tool, similar to ag and ack";
     homepage = "https://github.com/BurntSushi/ripgrep";
-    license = licenses.unlicense;
+    license = lib.licenses.unlicense;
     maintainers = [];
   };
 }
···
 
   doCheck = false;
 
-  meta = with lib; {
+  meta = {
     description = "A fast line-oriented regex search tool, similar to ag and ack";
     homepage = "https://github.com/BurntSushi/ripgrep";
-    license = with licenses; [ mit unlicense ];
-    maintainers = with maintainers; [];
+    license = with lib.licenses; [ mit unlicense ];
+    maintainers = with lib.maintainers; [];
   };
 }
 ```

doc/languages-frameworks/texlive.section.md

···
       runHook postInstall
     '';
 
-    meta = with lib; {
+    meta = {
       description = "A LaTeX2e class for overhead transparencies";
-      license = licenses.unfreeRedistributable;
-      maintainers = with maintainers; [ veprbl ];
-      platforms = platforms.all;
+      license = lib.licenses.unfreeRedistributable;
+      maintainers = with lib.maintainers; [ veprbl ];
+      platforms = lib.platforms.all;
     };
   };
 

doc/stdenv/meta.chapter.md

···
 Nix packages can declare *meta-attributes* that contain information about a package such as a description, its homepage, its license, and so on. For instance, the GNU Hello package has a `meta` declaration like this:
 
 ```nix
-meta = with lib; {
+meta = {
   description = "A program that produces a familiar, friendly greeting";
   longDescription = ''
     GNU Hello is a program that prints "Hello, world!" when you run it.
     It is fully customizable.
   '';
   homepage = "https://www.gnu.org/software/hello/manual/";
-  license = licenses.gpl3Plus;
-  maintainers = with maintainers; [ eelco ];
-  platforms = platforms.all;
+  license = lib.licenses.gpl3Plus;
+  maintainers = with lib.maintainers; [ eelco ];
+  platforms = lib.platforms.all;
 };
 ```