Limitedwidth page size fixes #148.

[lucaboesch]

It shoudn't affect Moodle ≤ 3.11.

[TamaroWalter]

All sites from Moodleoverflow have now a smaller width:
Before:
view.php:

discussion.php:

post.php:

index.php:

Now:
view.php:

discussion.php:

post.php:

index.php:

[lucaboesch]

Yeah, that is what I intended, @TamaroWalter.
From the student's point of view almost all activities have this user interface.
The broad pages are the one with tables, mostly addressed at lecturers (like grades, question bank participants etc).

[NinaHerrmann]

Thanks both of you for the work. Although I am still not sure whether I prefer the limitedwidth in general I highly appreciate, that you mentioned the inconsistency!
Thanks @lucaboesch for implementing and @TamaroWalter for reviewing and documenting!