Docs: doc-guide: update sphinx.rst Sphinx version number

Update the minimum version number to match both
Documentation/Changes and Documentation/conf.py.

Signed-off-by: Randy Dunlap <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: [email protected]
Cc: Mauro Carvalho Chehab <[email protected]>
Reviewed-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Jonathan Corbet <[email protected]>
Message-ID: <[email protected]>

Author: rddunlap

Documentation/doc-guide/sphinx.rst

@@ -28,7 +28,7 @@ Sphinx Install
 ==============
 
 The ReST markups currently used by the Documentation/ files are meant to be
-built with ``Sphinx`` version 2.4.4 or higher.
+built with ``Sphinx`` version 3.4.3 or higher.
 
 There's a script that checks for the Sphinx requirements. Please see
 :ref:`sphinx-pre-install` for further details.