Add build workflow

.github/workflows/build.yml

@@ -0,0 +1,41 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: 🛑 Cancel Previous Runs
+        uses: styfle/cancel-workflow-action@0.10.0
+        with:
+          access_token: ${{ github.token }}
+
+      - name: ⬇️ Checkout repo
+        uses: actions/checkout@v3
+
+      - name: ⎔ Setup node
+        uses: actions/setup-node@v3
+        with:
+          node-version: 18
+
+      - name: 📥 Download deps
+        uses: bahmutov/npm-install@v1
+        with:
+          working-directory: .
+
+      - name: 🏗️ Build
+        run: npm run build
+
+      - name: 📦 Package
+        run: 7z a release/extension.zip -r ./dist/*
+
+      - name: ⬆️ Upload extension artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: extension
+          path: ./release/extension.zip
+

.gitignore

@@ -1,2 +1,3 @@
 node_modules/
-dist/
+dist/
+release/