ReadTheDocs now allows us to configure some global configuration
options via a file in the repo rather than via the WebUI. Let's
do that so that we are managing our config as code too.
Change-Id: I8f829aeabd20d298fa98f697c092f833ea5eeee8 Signed-off-by: Thanh Ha <thanh.ha@linuxfoundation.org>