ci: add GitHub Actions CI

Author: Mattbusel

.github/workflows/ci.yml

@@ -0,0 +1,15 @@
+name: CI
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Configure
+        run: cmake -B build -DCMAKE_BUILD_TYPE=Release
+      - name: Build
+        run: cmake --build build --parallel