"Basegame" games shouldn't appear in the mod list

[tunbridgep]

In PR #22 a feature was added to allow specifying multiple "basegames". This essentially allows us to have multiple directories with various addons (model packs, etc), that are always loaded.

For instance, I have id1 and enhanced as basegames, which lets me store the Quake Enhanced models in a separate folder.

This is all good, except the "enhanced" folder shows up in the Mods menu too. This doesn't make any sense, as it will already be loaded by default anyway, and switching to it is identical to playing the standard game (id1).

This makes the Mods menu slightly more annoying to use, and feels wrong from a UX perspective.

Should a check be added so that if a particular game is being used as a basegame, it doesn't appear in the loadable mod list, as it's implied to be loaded by default anyway?