I tried adding some "Leaflet" type pictures to FLAC files and was surprised that EasyTAG didn't recognize the type of picture from the filenames -- leaflet08-09.jpg, leaflet10-11.jpg, leaflet12-13.jpg, and so on.

You will need:
- a directory of FLAC files
- some JPEG images with names like "leaflet01-02.jpg", "leaflet03-04.jpg", and so on.

Steps to reproduce:
1. Launch EasyTAG and point EasyTAG at a directory of FLAC files.
2. Select some FLAC files (it doesn't matter how many) and switch to the image tab in the right of the application to set some pictures.
3. Drag in the JPEG image files into the image area and see what type of image EasyTAG associates with the images.

EasyTAG seems to find front and back covers based on the filename, but not leaflet page images. My image filenames were added as front cover type images, so I had to edit each image type.

It would be good to either:
- add more substrings/regexes to automatically identify the image type based on the image filename,
- or (better still) let the user edit the mapping and ordering of image filename substring/regexes so the user could add "leaf(let)?" as a regular expression mapped to a "Leaflet page" image type.