bug#65818: 30.0.50; Mention NonGNU ELPA in C-h C-e

[Eshel Yaron]

`C-h C-e` displays `(info "(efaq)Packages that do not come with Emacs")`,
which says:

    There are other Emacs Lisp package archives [besides GNU ELPA].  To use
    additional archives, you can customize the 'package-archives' variable.
    Those archives have no affiliation with GNU Emacs, and we do not monitor
    how they are maintained.

This seems to disregard NonGNU ELPA, which is also included by default
in `package-archives`.  I'm not sure exactly where, but it seems like
this node should mention NonGNU ELPA as well.



In GNU Emacs 30.0.50 (build 4, x86_64-apple-darwin22.5.0, NS
 appkit-2299.60 Version 13.4 (Build 22F66)) of 2023-09-08
Repository revision: 46249f6139d1ea9aeb856febeffe2e4bac912e06
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2299
System Description:  macOS 13.4

Configured using:
 'configure 'CFLAGS=-g0 -O3' --with-native-compilation --with-json
 --with-imagemagick --with-tree-sitter --enable-link-time-optimization'

Configured features:
ACL DBUS GIF GMP GNUTLS IMAGEMAGICK JPEG JSON LCMS2 LIBXML2 MODULES
NATIVE_COMP NOTIFY KQUEUE NS PDUMPER PNG SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XIM ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-