Bump version number post-release (wikitext, 38cef92)

Now at 0.2.1. The next release will be 0.3. The next (and perhaps last) feature that I want to add prior to 1.0 will be markup for inserting img tags.

The syntax will most likely be "{{foo.png}}", inspired by Creole, as it should be nice and easy to parse.

Signed-off-by: Greg Hurrell <greg@hurrell.net>