Change TODO comment line highlighting

[MattDMo]

Moved from Neon Color Scheme issue 14.
@ChrisCalderon wrote:

Currently, it only highlights a TODO if there is one # at the front of the comment, but I like to use different levels, like #, ##, and ### for comments, and ### TODO doesn't get the pretty highlighting. I have no idea how syntax highlighting works, and I would change this myself and not bother you if I knew how. This is the one thing I wand to change about your amazing color scheme.