Change submodules for :doc: for feature projects

Change submodules for :doc: for feature projects

In feature projects there were tons of broken links
It does not make sense to link to anything but the projects
index file here, as we do not control what the project does past
having a doc/index.rst

The infrastructure guide is in a better shape but has two
broken links

The projects that are inactive will show greyed out links untill
they add an index.rst

Change-Id: I9cba2cc7dd355e3ed90cfe72b3646f25cd76558a
Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>