GitLab

* doc/emacs/programs.texi (Comment Commands): Fix description of for M-; on
blank lines.  Move documentation of comment-region here.
(Multi-Line Comments): Clarify the role of comment-multi-line.
Refer to Comment Commands for comment-region doc.
(Options for Comments): Refer to Multi-Line Comments for
comment-multi-line doc, instead of duplicating it.  Fix default
values of comment-padding and comment-start-skip.