Month names collection / metastudy

[nablator]

Added. For reference, I made a map of the locations of our entries that score 6+ points. This is basically the octembre-zone. A lot of entries are still with uncertain location though, I didn't add those.

Paris is doubtful because octembre is rare. Maybe there were a few Picards living there or (more likely) it was such a big production center of manuscripts that copies were certainly done of various books that originated elsewhere.