refactor footer community links

AI Prompts:
claude-sonnet-4-6: <ide_opened_file>The user opened the file ./_includes/footer.html in the IDE. This may or may not be related to the current task.</ide_opened_file> move the Community links into _data

Author: niccokunzmann

_data/footer_nav.yml

@@ -9,3 +9,13 @@ project:
     url: /ai-policy
   - label: Code of Conduct
     url: /code-of-conduct
+
+community:
+  - label: GitHub
+    url: https://github.com/pycalendar
+  - label: NLnet
+    url: https://nlnet.nl
+  - label: PyPI
+    url: https://pypi.org/search/?q=icalendar
+  - label: Funding
+    url: https://opencollective.com/python-icalendar

_includes/footer.html

@@ -16,10 +16,9 @@ <h4>Project</h4>
       <div class="footer-col">
         <h4>Community</h4>
         <ul>
-          <li><a href="https://github.com/pycalendar" target="_blank" rel="noopener">GitHub</a></li>
-          <li><a href="https://nlnet.nl" target="_blank" rel="noopener">NLnet</a></li>
-          <li><a href="https://pypi.org/search/?q=icalendar" target="_blank" rel="noopener">PyPI</a></li>
-          <li><a href="https://opencollective.com/python-icalendar" target="_blank" rel="noopener">Funding</a></li>
+          {% for item in site.data.footer_nav.community %}
+            <li><a href="{{ item.url }}" target="_blank" rel="noopener">{{ item.label }}</a></li>
+          {% endfor %}
         </ul>
       </div>
     </div>