Add Windows as installer runner

[Nutzzz]

While I entirely understand the reticence to provide a Lutris client for Windows (lutris/lutris#5369), would it be possible to add Windows as an installer runner, so 1. Windows website users, 2. a Lutris fork, and/or 3. other third party clients could leverage them? This website is a fairly complete reference for lots of games, but in particular of standalone fully libre games, and such games certainly deserve platform(s) to "lubricate" the discovery-to-play process (like Lutris does) for Windows users.

[strycore]

We could leverage Lutris to spam Windows users with pop-ups telling them to install Linux.