Docs: reference the new project Search settings page

Follow-up to #12843, which moved project search configuration out of the
Addons settings form into its own dedicated settings page. Update the
server-side search, subprojects, and addons docs to point users to the
new "Search" page under project Settings.

Author: claude

docs/user/addons.rst

@@ -43,8 +43,9 @@ Individual configuration options for each addon are available in :guilabel:`Sett
 #. Go to the new :term:`dashboard`.
 #. Click on a project name.
 #. Go to :guilabel:`Settings`.
-#. In the left bar, go to :guilabel:`Addons`.
-#. Configure each Addon individually.
+#. In the left bar, go to :guilabel:`Addons` to configure each Addon individually,
+   or go to :guilabel:`Search` to configure the search addon options
+   (which live on their own dedicated settings page).
 
 Integrating with Addons
 -----------------------

docs/user/server-side-search/index.rst

@@ -47,6 +47,9 @@ Special query syntax for more specific results
 Configurable
    Tweak search results according to your needs using a
    :ref:`configuration file <config-file/v2:search>`.
+   You can also enable or disable the search modal,
+   and toggle the subprojects filter shown inside it,
+   from your project's :guilabel:`Settings`, in the left bar, under :guilabel:`Search`.
 
 Ready to use
    We override the default search engine of your Sphinx project with ours

docs/user/subprojects.rst

@@ -94,10 +94,15 @@ they are presented with a flyout menu matching the subproject's versions and :do
 Search
 ------
 
-Search on the parent project will include results from its subprojects.
+Search on the parent project will include results from its subprojects,
+and readers can filter results by subproject from the search modal.
 If you search on the ``v1`` version of the parent project,
 results from the ``v1`` version of its subprojects will be included,
 or from the default version for subprojects that don't have a ``v1`` version.
 
 This is currently the only way to share search results between projects,
 we do not yet support sharing search results between sibling subprojects or arbitrary projects.
+
+The subprojects filter in the search modal can be turned off from the parent project's
+:guilabel:`Settings`, in the left bar, under :guilabel:`Search`,
+by unchecking :guilabel:`Show subprojects filter in search modal`.