docs: consolidate external URLs into a single Links nav item

Replace the second hidden toctree (which expanded each external URL
into its own navbar entry) with a dedicated links.rst landing page,
and add a single "links" entry to the main toctree. Top navbar now
shows User Guide / Contributor Guide / API Reference / Links — four
items, no wrapping. Clicking Links opens the page that lists GitHub,
Rust API Docs, Code of Conduct, and Examples.

Drop the external_links Examples entry from conf.py since the same
URL now lives on the Links page.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: timsaucer

docs/source/conf.py

@@ -138,12 +138,6 @@ def setup(sphinx) -> None:
             "icon": "fa-brands fa-rust",
         },
     ],
-    "external_links": [
-        {
-            "name": "Examples",
-            "url": "https://github.com/apache/datafusion-python/tree/main/examples",
-        },
-    ],
     "secondary_sidebar_items": [],
     "collapse_navigation": True,
     "show_nav_level": 2,

docs/source/index.rst

@@ -59,13 +59,4 @@ Example
    user-guide/index
    contributor-guide/index
    API Reference <autoapi/index>
-
-.. toctree::
-   :hidden:
-   :maxdepth: 1
-   :caption: Links
-
-   GitHub and Issue Tracker <https://github.com/apache/datafusion-python>
-   Rust API Docs <https://docs.rs/datafusion/latest/datafusion/>
-   Code of Conduct <https://github.com/apache/datafusion/blob/main/CODE_OF_CONDUCT.md>
-   Examples <https://github.com/apache/datafusion-python/tree/main/examples>
+   links

docs/source/links.rst

@@ -0,0 +1,30 @@
+.. 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.
+
+=====
+Links
+=====
+
+External resources for the DataFusion in Python project.
+
+.. toctree::
+   :maxdepth: 1
+
+   GitHub and Issue Tracker <https://github.com/apache/datafusion-python>
+   Rust API Docs <https://docs.rs/datafusion/latest/datafusion/>
+   Code of Conduct <https://github.com/apache/datafusion/blob/main/CODE_OF_CONDUCT.md>
+   Examples <https://github.com/apache/datafusion-python/tree/main/examples>