ad2play now accepts inline and block math display.
The implementation is clunky, but it does work.
New file: ad2tml which runs asciidoctor on a file and
then post-processes it so that the math is displayed
correctly.  This is just a kludge to compensate
for my lack of understanding of how asciidoctor
does math.
Added playground files
Improved drawing101
Documentation complete for now --- it is very rough.
Better text.
README updated.