Add github action to execute smart contract tests

Author: mikyjo

.github/workflows/main.yml

@@ -0,0 +1,23 @@
+name: Friendly Giant AI tests
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  unit:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22.x'
+      - name: Execute unit tests
+        run: |
+          npm ci
+          npm run test