What does this MR do?
In the announcement on the Commonmark Discourse, I said that there were some inconsistencies in the Markdown parser documentation. This contribution improves some of that, but not quite all of it.
- moves (sub)sections into proper places
- adds a distinction for the term GFM where necessary, because the acronym is also used for GitHub Flavored Markdown which is slightly different
- merges three tables in Special GitLab References into a single one, without adding any examples.