[3.12] gh-122085: Create dedicated page for deprecations (GH-122352) (#122375)

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

Author: 3 people

Diff for: Doc/contents.rst

@@ -14,6 +14,7 @@
    installing/index.rst
    howto/index.rst
    faq/index.rst
+   deprecations/index.rst
    glossary.rst
 
    about.rst

Diff for: Doc/deprecations/index.rst

@@ -0,0 +1,12 @@
+Deprecations
+============
+
+.. include:: pending-removal-in-3.13.rst
+
+.. include:: pending-removal-in-3.14.rst
+
+.. include:: pending-removal-in-3.15.rst
+
+.. include:: pending-removal-in-3.16.rst
+
+.. include:: pending-removal-in-future.rst

Diff for: Doc/tools/templates/indexcontent.html

@@ -33,6 +33,8 @@ <h1>{{ docstitle|e }}</h1>
          <span class="linkdescr">{% trans %}C API reference{% endtrans %}</span></p>
       <p class="biglink"><a class="biglink" href="{{ pathto("faq/index") }}">{% trans %}FAQs{% endtrans %}</a><br/>
          <span class="linkdescr">{% trans %}Frequently asked questions (with answers!){% endtrans %}</span></p>
+      <p class="biglink"><a class="biglink" href="{{ pathto("deprecations/index") }}">{% trans %}Deprecations{% endtrans %}</a><br/>
+         <span class="linkdescr">{% trans %}Deprecated functionality{% endtrans %}</span></p>
     </td></tr>
   </table>