Add instructions to readme on how to compile manually

[djmattyg007]

I don't use snap, and would prefer to just compile this software manually. I would appreciate it if you could add some instructions on how to compile it, and the software's dependencies, so that I can create an AUR package.

[keshavbhatt]

Sorry, I will add the instructions. You will require Qt5 or above to compile. run qmake in root of source directory, and then make to build the actual binary.