VKDoom is not detected as a ZDoom-alike

[leximayfield]

• https://vkdoom.org/
• https://github.com/dpjudas/VkDoom
• https://doomwiki.org/wiki/VKDoom

I do not have the ability to save statistics or load the latest save when using Doom Launcher with VKDoom. I would consider this port GZDoom-compatible, but it seems to have added changes to it that go above and beyond merely providing a vulkan renderer for GZDoom, so I think it is worth keeping around.

[nstlaurent]

No problem, I can add it for the next release :)