bug#58325: 28.1: Function-name error in documentation of M-j key binding

[Mark Harig via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

1. In the Emacs info manual, (emacs) Comment Commands, there is
   the sentence:

`C-M-j'
`M-j'
     Like `<RET>' followed by inserting and aligning a comment
     (`comment-indent-new-line').

However, C-h c M-j reports (for numerous (all?) major modes)

    M-j runs the command default-indent-new-line

Although the function `comment-indent-new-line' exists, the key
sequences C-M-j and M-j are not bound to it.

So, the sentence in the Emacs info manual needs to have
`comment-indent-new-line' changed to `default-indent-new-line'.


2. In the Emacs info manual, (emacs) Multi-Line Comments, there
   is the sentence:

      If you are typing a comment and wish to continue it to
      another line, type `M-j' or `C-M-j'
      (`comment-indent-new-line').

This sentence, too, needs to be changed to list the correct
function name (`default-indent-new-line').


3. Note also that only the second instance of
   `comment-indent-new-line' is found with an index search, and
   the match is not the definition of the key binding:

   Found ‘comment-indent-new-line’ in Command Index.  (Only match)

With the fix described above, an index entry should be added to
find `default-indent-new-line' in (emacs) Comment Commands.

(End of report.)