Add DocBoy

[Docheinstein]

Don't know if this is the right place/way to ask for it, feel free to shut down the request if it's not appropriate.

I'm currently developing DocBoy, a C++ GB emulator (DMG only by now) focused on accuracy.

At the moment it passes all the test roms of this repository it can support (i.e. no audio and GBC roms: I'm going to implement these soon), that is 155/263 (it passes also all the mealybug's roms and the other hard ones).

I've already forked the repo and added DocBoy (fork here) and I have GitHub's actions for automatic deployment of new releases (including Windows build, that is the one downloaded and used by my fork of the repo).

Any chance this could be included among the other emulators?

Thanks, and great job with this repo!

[daid]

At the moment I'm not actively working on this project, but I do take pull requests, as long as they are clean and the emulator runs in github actions just fine.