[tex-hyphen] Latin patterns update

[Élie Roux]

Dear All,

We've made some significant update in the Latin liturgical patterns last
year and things start to become quite stable. Can you please merge

https://github.com/gregorio-project/hyphen-la/blob/master/patterns/hyph.la.liturgical.txt

into tex-hyphen?

I can make a pull request on hyphenation/tex-hyphen if it's easier for you.

Thank you,
-- 
Elie