in your tx there is a 'language' dir. inside this you can find all translations.
you can take one (say hungarian or russian which are both 100% complete) and replace the hungarian/russian with serbian. the english line always starts with a ':' The next line is the translation of the English.
It is generally preferable to translate strings using the raw language files instead:
bitbucket.org/PhracturedBlue/deviation/s.../language?at=default
because these are used for all transmitters, but you can't use them directly on the transmitter (you need to pull the source and run 'make' to build the devo8/devo10 files) unlike the 1st method I mentioned. It is generally easiest to test with the emulator in my experience
