The doc currently refers to an in-tree directory
that we used to have in the distant past.
Also link to config.py and the share backend feature
support matrix where appropriate.
Change-Id: Ic22eba0cedb7c6c7c89ef129a8c6a007d97c7e3b
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>