Created attachment 85428 [details]
adds compose sequences for S and T with comma below

Compose sequences with <dead_belowcomma> exist, but very few keyboard
layouts contain that symbol.  So a more usual character is needed to be
able to easily compose Ș, ș, Ț and ț -- letters that occur regularly in
Romanian.  However, the obvious sequences with <comma> are already taken
for composing S and T with cedillas.

The semicolon is normally only used for composing letters with ogoneks --
but only vowels take ogoneks, so the character is free for consonants,
and thus in the attached patch <semicolon> is used to compose letters
with commas below.  It is somewhat fitting, because on most Romanian
keyboards the Ș is placed on that key, and the Ț next to it.