ddcbc-gtk - A GTK interface for ddc brightness control

I use multiple external monitors, and was tried of fiddling around with the monitor buttons to try to adjust my brightness. Thankfully, I discovered ddcutil, which was helpful, but I wanted an interface to do this. I also tried ddcui, however it was rather slow because it took the time to read all of the provided features each monitor had. So I created my own application to specifically adjust the brightness on each of my monitors. I hope to turn this into extensions for some of the desktop environments to better integrate this into the desktop. Feel free to create issues/pull requests as needed - this is my first open source project (as trivial as it is) so go easy on me haha.