AMIDST PANDEL: Sphinx-documentated the specifications for its Main
class. DOES NOT COMPILE YET!

* pandel: Move it out of ``wltp.model``, in a separate module, and
renamed ``ModelMaker-->Pandel``.
* docs: Various fixes from complaints, and for RTD.
* build: deps: prefixtree WARN: Not installable yet!!
* tests: wltp_db: some tests fail spurisously!
docs: Clean README.rst from Sphinx-only construct for PyPi to work.

* ci: Add script to Ensure README valid ReST for PyPI.
* tests: wltp_db: Mark heinz-db results as max-gear-time: 2sec.
docs: Add FAQ.

* docs: Set sphin's default role to 'obj'.
AMIDST PANEDL-2: Docs almost ready, before experimenting with modifying
jsonrules. FAIL, doctests LY FAIL!