Enhanced rendering of docs, expanded introductory section.
Documented `perm` module, alphabetically sorted documenation for
modules, replaced dead recorded demo links with new links,
documented apt package blacklisting capability.
Change-Id: Ifd889efe73287c13d839ab40b1a78ffa357fd00e
The previous README file for Divingbell did not render correctly
as a md. This change converts it to a small RST file.
Change-Id: Iabfc3eb6ed763ddf306d85f85399f2f3f99069ae