Offer vocab list page per user/organization

[acka47]

This was addressed in today's meeting by the OER metadata group of DINI AG KIM. It would be nice to have an overview of all vocabs published with SkoHub by a particular GitHub/GitLab organization or user. For example, at https://skohub.io/hbz/ should be a list of all vocabs from https://skohub.io/hbz/vocabs-edu/ and https://skohub.io/hbz/lobid-vocabs/ (where currently nothing is listed so that this is not a good example but I don't know a better one).

[sroertgen]

@acka47 I think this is somewhat done with skohub-io/skohub-webhook@94eaf69

Please close if ok