Syllabification issues for words with श्च

[shardulc]

These words don't get syllabified:

> transcribe निश्चित
niɕt͡ɕit̪ə
> transcribe निश्चय
niɕt͡ɕəjə
> transcribe नरश्च गजश्च
nəɹəɕt͡ɕə gəd͡ʑəɕt͡ɕə

But this one does:

> transcribe पुनःश्च
pu.ˈnəhɕ.t͡ɕə

In my opinion, the code should reach this condition but doesn't—might be a starting point for debugging.

(Note: at first I thought this was an issue relating to zero-width non-joiners, but it wasn't. Nevertheless, the presense of ZWNJs in the input gives a warning in the script. I believe Sanskrit text does not use ZWNJs but it might be good to explicitly ignore them anyway.)

[shardulc]

Another note: when multiple words are inputted, if syllabification fails for one of them, then the entire input is printed unsyllabified. In my opinion, only the troublesome word should be printed unsyllabified.