fix: add workflow

.github/workflows/build.yml

@@ -0,0 +1,22 @@
+name: Build
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - name: Use Node.js
+      uses: actions/setup-node@v2
+      with:
+        node-version: '18'
+
+    - name: Install dependencies
+      run: yarn
+
+    - name: Build
+      run: yarn build