Convention is now:
If you include a picture in `/<path>/<file>.rst`, your picture must
follow the path: `images/<path>/<file>_<some_title>.<extension>`.

For example: if you want to include the picture `mypicture.png` in
`/a/cool/path/myguide.rst`, move your picture file to `/a/cool/path/myguide_mypicture.png`.