Adds Stride3D, the open-source c# game engine

Signed-off-by: Tebjan Halm <tebjan@gmail.com>

Author: tebjan

collections/game-engines/index.md

@@ -58,6 +58,7 @@ items:
  - luanti-org/luanti
  - defold/defold
  - openfl/openfl
+ - stride3d/stride
 display_name: Game Engines
 created_by: leereilly
 ---