Add support for markdown

[richienyhus]

https://github.com/paulsmith/cMarkdown
http://draketo.de/proj/pymarkdown_minisite/readme.html
http://packages.python.org/Markdown/
https://github.com/trentm/python-markdown2
https://github.com/waylan/Python-Markdown
https://github.com/Orc/discount
https://github.com/joeyespo/grip

[pulkomandy]

Pandoc (http://pandoc.org/) could be reviewed as a way to convert between various markup formats.

[richienyhus]

Yea, It would be easier to just use pandoc, although pandoc is GPL and and this app is MIT.

[pulkomandy]

Ideally we would use pandoc as a translator add-on and the app would make use of it through the add-on interface. Not only this would make it easier to add other formats in the future, but it would also solve the licensing issue, because the translator API isolates the GPL code inside the translator add-on.

And it would make the conversion between markup languages available to other apps, as well.