[Feature] Doom WADs support

[NotaInutilis]

I'd just like to manage Doom WADs with Romm.

WADs are packaged mods for Doom, Doom 2 and other Doom engine games. It's a well documented format.
https://doomwiki.org/wiki/WAD
https://en.wikipedia.org/wiki/Doom_modding

A lot of those have IGDB pages. They are listed as mods for Doom 1 or 2 and usually have the "wad" tag. Some examples below.
https://www.igdb.com/games/thatchers-techbase
https://www.igdb.com/games/my-house
https://www.igdb.com/categories/wad

In the way that RomM can handle these files, we can make the very shoddy analogy that the PWAD (mod) is a rom, the IWAD (original game, doom.wad, doom2.wad) is a bios and the game engine is an emulator.

Moreover, since Doom 1 and 2 are open source, there are a lot of source ports (GZdoom, Boom,...) that allow Doom to run on anything, including a web browser! A source port could be included in RomM along with all its emulators. Unfortunately, I don't have a suggestion for which one to use.