chore: add docs workflow (#655)

Author: jeremydw

.github/workflows/docs.yml

@@ -0,0 +1,60 @@
+name: Deploy rootjs.dev
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: '8.9.0'
+
+      - name: Get pnpm store directory
+        shell: bash
+        run: |
+          echo "STORE_PATH=$(pnpm store path --silent)" >> $GITHUB_ENV
+
+      - name: Setup pnpm cache
+        uses: actions/cache@v4
+        with:
+          path: ${{ env.STORE_PATH }}
+          key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
+          restore-keys: |
+            ${{ runner.os }}-pnpm-store-
+
+      - name: Install dependencies
+        run: |
+          pnpm install
+          pnpm add -g firebase-tools@13.35.1
+
+      - name: Authenticate to Google Cloud
+        uses: google-github-actions/auth@v2
+        with:
+          credentials_json: ${{ secrets.GOOGLE_CREDENTIALS }}
+
+      - name: Setup Google Cloud CLI
+        uses: google-github-actions/setup-gcloud@v2
+        with:
+          project_id: rootjs-dev
+
+      - name: Build root
+        run: pnpm run build
+
+      - name: Build and deploy rootjs.dev
+        working-directory: docs
+        run: pnpm run deploy