bug#35876: "q" when article is full-screen should return us to the *Summary* buffer, not the *Group* buffer

[積丹尼 Dan Jacobson]

This should be the default:
(define-key gnus-article-mode-map [?q] 'gnus-summary-expand-window)

Compare mutt etc. all other such programs.

You see after the user hits
"h runs the command gnus-summary-select-article-buffer"
he is now totally in "Article level mindset" so "q" should take him up
one level, not two.

Yes, he could just hit "=" but his mind does not think that way.

(There should be a two letter command for users who really want to exit
two levels.)

Gnus v5.13