Add examples of Rst and markdown

[hupili]

I see in one post that this tool support Rst and markdown. It's good to add some examples of them. Or at least show the ability in README. New users can get it by first glance.

redirected from #13

[mfrasca]

I used this one:
http://www.southampton.ac.uk/~fangohr/computing/rst/rst.txt

works fine, but you must rename it to have an extension ".rst".
the command line for it:
txt2epub /tmp/demo.epub --title demo --creator "sourceforge" --date 2013-08-27 /tmp/rst.txt

I added a --type rst, but it had no effect, this should be addressed.