* New module: Text.Pandoc.Writers.Ms.
* New template: default.ms.
* The writer uses texmath's new eqn writer to convert math
to eqn format, so a ms file produced with this writer
should be processed with `groff -ms -e` if it contains
math.
These were confusing.
Now we rely on the +raw_tex or +raw_html extension with latex
or html input.
Thus, instead of
--parse-raw -f latex
we use
-f latex+raw_tex
and instead of
--parse-raw -f html
we use
-f html+raw_html
