Add a simple CI

Author: arrowd

.github/workflows/build.yml

@@ -0,0 +1,32 @@
+---
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-24.04
+    defaults:
+      run:
+        shell: cpa.sh {0}
+    steps:
+      - name: Repository checkout
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+
+      - name: Start VM
+        uses: cross-platform-actions/action@5ea7e8e4677bd726033a10b094ba1c5762b15dee # v1.3.0
+        with:
+          operating_system: freebsd
+          version: '15.1'
+          architecture: 'x86_64'
+      - name: Run commands
+        run: |
+          sudo pkg install -y cmake-core
+          sudo make install
+          make test