Add GitHub workflow to update boostlook.css in website-v2 on master push

.github/workflows/update-website-v2.yml

@@ -0,0 +1,35 @@
+name: Update boostlook.css in website-v2
+
+on:
+  push:
+    branches: [ "master" ]
+    paths:
+      - 'boostlook.css'
+
+jobs:
+  update-css:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout boostlook repository
+        uses: actions/checkout@v3
+
+      - name: Checkout website-v2 repository
+        uses: actions/checkout@v3
+        with:
+          repository: boostorg/website-v2
+          ref: develop
+          path: website-v2
+          token: ${{ secrets.WEBSITE_V2_PAT }}
+
+      - name: Copy boostlook.css to website-v2
+        run: |
+          cp boostlook.css website-v2/static/css/boostlook.css
+
+      - name: Commit and push changes
+        working-directory: website-v2
+        run: |
+          git config user.name "${{ github.actor }}"
+          git config user.email "${{ github.actor }}@users.noreply.github.com"
+          git add static/css/boostlook.css
+          git commit -m "Update boostlook.css from boostlook repository"
+          git push origin develop