Add gamedev and CG resources

[ultramarinebicycle]

Especially Blender, Godot, and open source books. Also, ArmorPaint, Armory, UPBGE and can be added, though I'm not up to date on those.

[BlackGoku36]

CG resources are here: developersIndia/wiki#18
Don't think anyone is going to be interested in Armory or UPBGE nowadays