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>
diff --git a/doc/sphinx/requirements.txt b/doc/sphinx/requirements.txt
index 13e0327..12c5772 100644
--- a/doc/sphinx/requirements.txt
+++ b/doc/sphinx/requirements.txt
@@ -15,6 +15,7 @@
 snowballstemmer==2.2.0
 Sphinx==8.1.3
 sphinx-prompt==1.9.0
+sphinx-reredirects==0.1.5
 sphinx-rtd-theme==3.0.1
 sphinxcontrib-applehelp==2.0.0
 sphinxcontrib-devhelp==2.0.0