The best way to help the library project is to just do some reviews of assets. Document your findings via screenshots or text as a comment on the pull request.
And if you are interested in doing this on a regular basis then I suspect there will be some option to add you to the team (the “you” here is not meant for @StefanHamminga in particular but for any interested reader).
- For footprints check the measurements of the contribution against the suggested footprint within the datasheet (either with the new measurement tools found in the nightly builds or by use of an external tool like i described here Tutorial: How to check footprint correctness?)
- Exception are footprints for standardized packages like QFN/DFN, SOIC and similar which should really go through the footprint generators. These are then best checked in the pull request of the footprint generator (Ideally no tools required as that can be completely done by looking at the diff on gitlab)
- For symbols check the pin numbering and electrical types against the datasheet. Check that the assigned footprint is correct (should be obvious from the name of the footprint).
- For 3d models I generally am out of the loop about how to best check them. Back when I was still reviewing them (a few years ago) I basically only checked if they fit the footprint well enough to look ok from within KiCad.
Sadly i am currently not really able to help out much as i want to finish my thesis first. Once this is done i at least plan to go back to helping out on the footprint library and on the footprint generators again.