Item9693: Add some missing documentation

TML and WikiText are used here and there but are not really defined
anywhere.  Add topics to define them so that they'll link when used.

Also ACRONYM had an extraneous STOPINCLUDE macro without any
corresponding START.

git-svn-id: http://svn.foswiki.org/trunk/core@17516 0b4bb1d4-4e5a-0410-9cc4-b2b747904278