doc: Start improving our pytest documentation

Begin the work of documenting all of our pytests. To do this, we should
have a directory under develop for it as there will be a large number of
new files. As the current document is referenced externally in a number
of locations, add the sphinx_reredirects module so that we can redirect
from the old location to the new.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

doc/develop/ci_testing.rst

@@ -18,7 +18,7 @@ be built with mingw to run on Windows.
 Each of the pipelines is written in such as way as to be a "world build" style
 test and as such we try and build all possible platforms.  In addition, for all
 platforms that support being run in QEMU we run them in QEMU and use our pytest
-suite.  See :doc:`py_testing` for more information about those tests.
+suite.  See :doc:`pytest/usage` for more information about those tests.
 
 Azure Pipelines
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