With the syntax here I can confirm local changes in `latin.js` will be picked up by Git and anything else will not:

    timdream:~/repo/gaia keyboard-remove-ime$ echo hello Git > apps/keyboard/js/imes/latin/latin.js
    timdream:~/repo/gaia keyboard-remove-ime*$ touch apps/keyboard/js/imes/sdfadsf
    timdream:~/repo/gaia keyboard-remove-ime*$ g st
    ## keyboard-remove-ime
     M apps/keyboard/js/imes/latin/latin.js
    timdream:~/repo/gaia keyboard-remove-ime*$