add github workflow

.github/workflows/validate.yml

@@ -0,0 +1,16 @@
+name: validate
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - run: make all