add github workflow

Author: WinterMute

.github/workflows/ci.yml

@@ -0,0 +1,16 @@
+name: C/C++ CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: ubuntu-latest
+    runs-on: ubuntu-latest
+    container: devkitpro/devkitarm:latest
+ 
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Build
+      run: |
+        make -j