Automatically Import Map Banner Images

[gamemann]

Similar to #5, I'd like to automatically import server map banner images for as many maps as we can. This is a lot more complicated than #5 because there are a lot of maps.

[gamemann]

Also forgot to note, I can upload map images through the admin portal, similar to country flags. I've uploaded a few map banners in Counter-Strike 2 to test, but there are too many maps to handle this manually.