PatristicTextArchive/pta_manuscripts: Status quo

First release of the data for Zenodo.

At the moment, for the greatest part the database contains only rudimentary data on the manuscripts containing texts edited in the Patristic Text Archive (PTA) by the project „Alexandrinische und antiochenische Bibelexegese der Spätantike“. That data is widely based on data provided by Pinakes and, for manuscripts transmitting the homilies of Severian of Gabala, on handwritten notes by Karl-Heinz Uthemann.