Deactivate sidebar for release notes

[timhoffm]

The release note page is only a structured collection of links to sub-pages. The sidebar would repeat all the titles of the sub-pages and thus basically repeat all the content of the page. Even worse, it does not contain the version sectioning structure of the release notes page itself.

It's thus best to deactivate the sidebar here.

Related to #27690 (comment)

[timhoffm]

Build docs:
https://output.circle-artifacts.com/output/job/d4fe23e6-b802-4d90-b879-6fb198911ab2/artifacts/0/doc/build/html/users/release_notes.html

[dstansby]

I'm not a huge fan of this because the position of the main content of the page shifts to the left (where the sidebar was) relative to other pages.

I think this issue is symptomatic of the page tree needing change instead of removing the sidebar altogether. How about adding another layer of pages above the release notes page, each page being a different version number. Here's a quick go, with just 3.8 and 3.7 changed. Would be happy to do the rest of the versions and PR it if someone else likes this.

diff --git a/doc/users/release_notes.rst b/doc/users/release_notes.rst
index 32bd024320..d3aad9c888 100644
--- a/doc/users/release_notes.rst
+++ b/doc/users/release_notes.rst
@@ -10,31 +10,18 @@ Release notes
 .. include from another document so that it's easy to exclude this for releases
 .. ifconfig:: releaselevel == 'dev'
 
-   .. include:: release_notes_next.rst
+    .. toctree::
+        :glob:
+        :maxdepth: 2
 
+        release_notes_next.rst
 
-Version 3.8
-^^^^^^^^^^^
 .. toctree::
-    :maxdepth: 1
-
-    prev_whats_new/whats_new_3.8.0.rst
-    ../api/prev_api_changes/api_changes_3.8.1.rst
-    ../api/prev_api_changes/api_changes_3.8.0.rst
-    github_stats.rst
-    prev_whats_new/github_stats_3.8.0.rst
-
-Version 3.7
-^^^^^^^^^^^
-.. toctree::
-    :maxdepth: 1
+    :glob:
+    :maxdepth: 2
 
-    prev_whats_new/whats_new_3.7.0.rst
-    ../api/prev_api_changes/api_changes_3.7.0.rst
-    prev_whats_new/github_stats_3.7.3.rst
-    prev_whats_new/github_stats_3.7.2.rst
-    prev_whats_new/github_stats_3.7.1.rst
-    prev_whats_new/github_stats_3.7.0.rst
+    release_notes/3.8.rst
+    release_notes/3.7.rst
 
 Version 3.6
 ^^^^^^^^^^^
diff --git a/doc/users/release_notes/3.7.rst b/doc/users/release_notes/3.7.rst
new file mode 100644
index 0000000000..b70a87d0f1
--- /dev/null
+++ b/doc/users/release_notes/3.7.rst
@@ -0,0 +1,13 @@
+===========
+Version 3.7
+===========
+
+.. toctree::
+    :maxdepth: 1
+
+    ../prev_whats_new/whats_new_3.7.0.rst
+    ../../api/prev_api_changes/api_changes_3.7.0.rst
+    ../prev_whats_new/github_stats_3.7.3.rst
+    ../prev_whats_new/github_stats_3.7.2.rst
+    ../prev_whats_new/github_stats_3.7.1.rst
+    ../prev_whats_new/github_stats_3.7.0.rst
diff --git a/doc/users/release_notes/3.8.rst b/doc/users/release_notes/3.8.rst
new file mode 100644
index 0000000000..8e082fff84
--- /dev/null
+++ b/doc/users/release_notes/3.8.rst
@@ -0,0 +1,12 @@
+===========
+Version 3.8
+===========
+
+.. toctree::
+    :maxdepth: 1
+
+    ../prev_whats_new/whats_new_3.8.0.rst
+    ../../api/prev_api_changes/api_changes_3.8.1.rst
+    ../../api/prev_api_changes/api_changes_3.8.0.rst
+    ../github_stats.rst
+    ../prev_whats_new/github_stats_3.8.0.rst

[timhoffm]

Agreed, the layout change is undesireable. We can work around that by an empty sidebar -> updated this PR.

I would alternatively fine with the restructuring. Note however, that the links on the sidebar (e.g. "Version 3.8.0") would then only go to the index page of that version and you need to click a second link to get to some content. So the sidebar links for the restructured content are not too practical.

[jklymak]

This seems good. Could put the front page sidebar in there, but this is fine.

[timhoffm]

I rather leave an empty sidebar. The front page sidebar has cheatsheets and the donate button, which are out of scope in the changelog context.