Add 'title' command.
Add 'title' command.

This adds a 'title' command to make it easier to add titles to images.
It basically takes an image filename and a title, and will write a
corresponding .md file with the Title attribute.

Signed-off-by: Toke Høiland-Jørgensen <c739cf9ea9032889618db8b95a03da66fcc9867e@toke.dk>

kontza/sigal,kontza/sigal,kontza/sigal