Mentioning Emacs' AUTHORS file in admin/make-tarball.txt.

[Lute Kamstra]

It just occurred to me that admin/make-tarball.txt doesn't mention
Emacs' AUTHORS file.  As I understand it, this file needs to be
regenerated before a release.  What about the following entry?

3.  Regenerate Emacs' AUTHORS file (M-x load-file RET
    lisp/emacs-lisp/authors.el RET, then M-x authors RET, then save
    the *Authors* buffer).  This may require fixing syntactically
    incorrect ChangeLog entries beforehand.


  Lute.