I was thinking that it would be nice to have an automatic way to generate a
rendered .png of an entire level.

Ideally this would have a command-line interface, so it would be easy to dump an
image copy of all levels.

I think this would be useful for the following cases:
1) Documentation (it would be nice to have a single map showing where everything is)
2) Level changes (changes in pictures are more obvious than changes in text files)