Deliver EPUB versions of plays in Download tab

[lehkost]

We could do that using the official TEI stylesheets.

[ingoboerner]

Maybe use TEI Garage to generate: https://teigarage.tei-c.org/#
API Documentation of the RestAPI:
https://raw.githubusercontent.com/TEIC/TEIGarage/refs/heads/main/src/main/webapp/openapi.json