Hide redundant table of contents from docs homepage

Currently the ToC  appears twice on the docs home page
`https://cheroot.cherrypy.dev/en/latest/`: both in the left hand
selection panel and in the main contents next to it. This commit
removes the duplicated content in the main panel.

Author: julianz-

docs/changelog-fragments.d/818.doc.rst

@@ -0,0 +1,7 @@
+Removed the redundant table of contents from the documentation home page.
+
+Previously the table of contents appeared twice on the :doc:`docs home page
+<index>`: both in the left hand
+selection panel and in the main contents next to it.
+
+-- by :user:`julianz-`

docs/index.rst

@@ -6,21 +6,25 @@ Welcome to Cheroot documentation!
 .. toctree::
    :maxdepth: 1
    :glob:
+   :hidden:
 
    history
 
 .. toctree::
    :caption: Contributing
+   :hidden:
 
    contributing/guidelines
 
 .. toctree::
    :caption: Maintenance
+   :hidden:
 
    contributing/release_guide
 
 .. toctree::
    :caption: Reference
+   :hidden:
 
    devguide
    Private (dev) API autodoc <pkg/modules>