manual: add node to languages & frameworks

fixes #18609

doc/default.nix

@@ -60,6 +60,10 @@ pkgs.stdenv.mkDerivation {
       inputFile = ../pkgs/development/idris-modules/README.md;
       outputFile = "languages-frameworks/idris.xml";
     }
+  + toDocbook {
+      inputFile = ../pkgs/development/node-packages/README.md;
+      outputFile = "languages-frameworks/node.xml";
+    }
   + toDocbook {
       inputFile = ../pkgs/development/r-modules/README.md;
       outputFile = "languages-frameworks/r.xml";

doc/languages-frameworks/index.xml

@@ -21,6 +21,7 @@ such as Perl or Haskell.  These are described in this chapter.</para>
 <xi:include href="idris.xml" /> <!-- generated from ../../pkgs/development/idris-modules/README.md  -->
 <xi:include href="java.xml" />
 <xi:include href="lua.xml" />
+<xi:include href="node.xml" /> <!-- generated from ../../pkgs/development/node-packages/README.md  -->
 <xi:include href="perl.xml" />
 <xi:include href="python.xml" />
 <xi:include href="qt.xml" />

pkgs/development/node-packages/README.md

@@ -1,5 +1,7 @@
-NPM packages
-===========
+Node.js packages
+===============
+To add a package from [NPM](https://www.npmjs.com/) to nixpkgs:
+
  1. Install node2nix: `nix-env -f '<nixpkgs>' -iA node2nix`.
  2. Modify `pkgs/development/node-packages/node-packages.json`, to add, update,
     or remove package entries.