Support generating Monastic with epubgen2.sh

[jkuester]

First of all, thank you to everyone who has put so much effort into this great project! I would like to be able to generate eReader files for the Monastic rubric.

I see in the epubgen2.sh script that "Monastic" is not one of the supported rubrics. Further, it seems that "Monastic" is not listed in the supported @versions in epub/Eofficium.pl.

Am I missing something here and there is actually a way to generate epub/mobi files for the Monastic rubric?

Alternatively, is it likely to be a heavy lift to add this support? I do not have much perl experience, but I would be interested to try my hand at adding support if there are not any heavy blockers... Thank you!

[mbab]

filled with #4439
if Missa is not required try https://mbab1.gitlab.io/divinumofficium.epub/