GitHub integration to show new symbols and footprints

[adamgreig]

Make a neat service that sees new pull requests, notices if there are any new .yaml or .kicad_mod files, and if so, renders them and comments with a picture.

[seppestas]

I was planning to add this sort of functionality to https://github.com/productize/kicad-file-render-service. Let me know if you are still interested in this use-case.