ci: add build workflow

.github/workflows/build.yml

@@ -0,0 +1,21 @@
+name: Build
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+      - run: corepack enable
+      - run: pnpm install
+      - run: pnpm build
+      - uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist