doc: update doc generation info

Update the versions of tools used to generate documentation locally and
include a description of the message filtering now included in the doc
build Makefile (formerlly only done in the CI scripts).

Also, include the documentation docs in the developer guides to help
folks that want to contribute and generate docs locally.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
2 files changed