Add docs about the :NavbarGuidesUrl setting. #6877

doc/sphinx-guides/source/installation/config.rst

@@ -1459,6 +1459,14 @@ Note: The "About" link will not appear in the navbar until this option is set.
 
 ``curl -X PUT -d http://dataverse.example.edu http://localhost:8080/api/admin/settings/:NavbarAboutUrl``
 
+:NavbarGuidesUrl
+++++++++++++++++
+
+Set ``NavbarGuidesUrl`` to a fully-qualified URL which will be used for the "User Guide" link in the navbar.
+
+Note: by default, the URL is composed from the settings ``GuidesBaseUrl`` and ``GuidesVersion`` below.
+
+``curl -X PUT -d http://example.edu/fancy-dataverse-guide http://localhost:8080/api/admin/settings/:NavbarGuidesUrl``
 
 :GuidesBaseUrl
 ++++++++++++++