Include the python script that generates a catalog of footprints

[cvgaviao]

The script that was provided here [1] is very awesome. it generates a pdf catalog containing all footprints and with its image preview.
Maybe you can add a caller script that will traverse all repositories and generate a catalog for each one inside a common directory.

[1] - https://forum.kicad.info/t/full-footprint-library-lists-ideally-in-ascii/3334/9

[kasbah]

I started to have a go at this in #12 but didn't get further than including the script. Pull-request welcome!