[Readme] Playstation: Genesis Plus GX

[FateForWindows]

I believe this is meant to be another core or system, but Playstation is listed as being able to run under the Genesis Plus GX core. I assume this is meant to say Sega CD but I'm not entirely sure.

[Formedras]

This is likely to be more a general Libretro thing; on most implementations of Libretro, including RetroArch, when prompted for what core to use, the frontend lists all cores that can handle the file's type, based on file extension. Cores for disc-based systems near-universally accept the ISO format, and as such, a Mega-CD core will be listed right along a PS1 core, even if you're loading a GameCube ISO.