Convert Docs Project Structure to facilitate faster docs builds

Follow up with LF's Thanh Ha on changing docs project structure to eliminate submodules. This new structure will increase docs build times.

Amount of effort is unknown.

The Docs project structure changes - we have to use intersphinx linking (see OpenDaylight and      https://docs.releng.linuxfoundation.org/en/latest/project-documentation.html)

Then each component must be updated - the docs folder must have conf.py etc added to it.

Also we cannot change the RST gate job to fail on warning if all the docs are compiling with every job.