Setup GitHub Actions CI

[karnkaul]

AC:

• Windows x64
  • Visual Studio | Release
• Linux x64
  • Ninja Multi-Config / gcc | Release
  • Ninja Multi-Config / clang | Release
• Prefer speed of response if something breaks over exhaustive job sets

Reference

[Rinzii]

Added in a starter file but it will likely need some tuning before it works correctly. I’ll go over it more tomorrow. ^^