Doc updates
Lower plumbing for detecting abbreviations
Trying to get abbr to work
tweak
Add abbreviations to mmark.

Support abbreviations, like:

    *[HTML]: Hyper Text Markup Language

Now you can use HTML anywhere in the document.
Fix tests and the implementation.
It does work
simplify the normaltext output
Fix abbreviation.

Outputting and checking abbreviations now works.
Update documentation as well
Check length before doing an i+1
Make it an proper extension
Merge branch 'abbr'
Update the README a bit
base framework for table footer
merge conflict