doc: hide main table of contents

Hide the main table of contents so that it doesn't show up in the actual
documentation index, only in the side bar. This helps keep the index
less cluttered and to the point.

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

doc/index.rst

@@ -93,7 +93,7 @@ licensing, as described in :ref:`Zephyr_Licensing`.
 
 .. toctree::
    :maxdepth: 1
-   :caption: Contents
+   :hidden:
 
    introduction/index.rst
    develop/index.rst