[SPARK-52105] Provide Helm Chart repository

### What changes were proposed in this pull request?

This PR aims to publish `gh_pages` branch to https://apache.github.io/spark-kubernetes-operator .

### Why are the changes needed?

To use it as a Helm Chart repository.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

This should be tested after merging.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#191 from dongjoon-hyun/SPARK-52105.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: dongjoon-hyun

.github/workflows/pages.yml

@@ -0,0 +1,48 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+name: GitHub Pages deployment
+
+on:
+  push:
+    branches:
+      - gh-pages
+
+jobs:
+  docs:
+    name: Build and deploy documentation
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+      pages: write
+    environment:
+      name: github-pages # https://github.com/actions/deploy-pages/issues/271
+    if: github.repository == 'apache/spark-kubernetes-operator'
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: '.'
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4