chore: add github action script

Author: randy3k

.github/workflows/main.yaml

@@ -0,0 +1,33 @@
+name: main
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    name: Run npm tests
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [18]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: "npm"
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Run Jest tests
+        run: npm run test
+
+      - name: Run grammar tests
+        run: npm run test:grammar