Docs for hidding "On ..." section from versions menu (#4547)

This is not a real solution, but currently is the only way of doing this.

docs/guides/remove-edit-buttons.rst

@@ -2,11 +2,15 @@ Removing "Edit on ..." Buttons from Documentation
 =================================================
 
 When building your documentation, Read the Docs automatically adds buttons at
-the top of your documentation that point readers to your repository to make
+the top of your documentation and in the versions menu that point readers to your repository to make
 changes. For instance, if your repository is on GitHub, a button that says "Edit
-on GitHub" is added to your documentation to make it easy for readers to author
+on GitHub" is added in the top-right corner to your documentation to make it easy for readers to author
 new changes.
 
+
+Remove links from top-right corner
+----------------------------------
+
 The only way to remove these links currently is to override the Read the Docs
 theme templates:
 
@@ -22,5 +26,25 @@ The new ``breadcrumbs.html`` should look like this::
     {% block breadcrumbs_aside %}
     {% endblock %}
 
+
+Remove "On ..." section from versions menu
+------------------------------------------
+
+This section can be removed with a custom CSS rule to hide them.
+Follow the instructions under :doc:`adding-custom-css` and put the following content into the ``.css`` file:
+
+.. code-block:: css
+
+   /* Hide "On GitHub" section from versions menu */
+   div.rst-versions > div.rst-other-versions > div.injected > dl:nth-child(4) {
+       display: none;
+   }
+
+
+.. warning::
+
+   You may need to change the ``4`` number in ``dl:nth-child(4)`` for a different one in case your project has more sections in the versions menu.
+   For example, if your project has translations into different languages, you will need to use the number ``5`` there.
+
 Now when you build your documentation, your documentation won't include an edit
 button or links to the page source.