Adds URL for 'Sphinx documentation' close to its use.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

source/clear-linux/reference/collaboration/documentation/cross.rst

@@ -150,5 +150,4 @@ Use of the ``.. inclusion::`` for :ref:`rest` is shown below.
    :start-after: incl-restructured-text-overview:
    :end-before: incl-restructured-text-overview-end:
 
-
 .. _Oregon: http://traveloregon.com/

source/clear-linux/reference/collaboration/documentation/rest.rst

@@ -14,6 +14,8 @@ documentation. This section contains the preferred methods for using the
 `Sphinx documentation`_ for the complete list of available markup and use
 as much markup as possible.
 
+.. _Sphinx documentation: http://www.sphinx-doc.org/en/stable/markup/index.html
+
 Remember: **Changing incorrect markup is easier than adding markup from
 scratch.**
 
@@ -45,5 +47,3 @@ templates supplied.
    code
    contents
 
-
-.. _Sphinx documentation: http://www.sphinx-doc.org/en/stable/markup/index.html