Languages for which some unique descriptions remain are kept.
This cleaning removes the following rules that were implemented in no
language:
[S1947, S2085, S2086, S2609, S2610, S2614, S2643, S2773, S2776, S3268,
S3272, S3361]
When an include is not surrounded by empty lines, its content is inlined
on the same line as the adjacent content. That can lead to broken tags
and other display issues.
This PR fixes all such includes and introduces a validation step that
forbids introducing the same problem again.
