request: separate "a-e" in "euouae"

(Not sure where to comment on LatinSyllabification.py since the text_alignment repo is archived... @timothydereuse ?)

The set-up of the syllabification code is such that all instances of "ae" are treated as one syllable/diphthong. However, in practice this spelling is comparatively rare in medieval manuscripts. What _isn't_ rare, at least in chant manuscripts, is the "word" euouae, which we see in about half the chants and which has to be corrected in Neon to separate the a and the e every single time. The same problem also happens in the parts of CantusDB that use this syllabification code to align Volpiano.
Ideally this word should probably just raise an exception to the rules and be e-u-o-u-a-e . If necessary I think it would actually be preferable to have this be correct and usages of the diphthong be wrong than the other way around, because this is by far the more common situation in chant manuscripts...