index.md was moved over to it's own directory `site/` and
`site-publishing/` contains static page generator that takes that
content and turns it into a html webpage.

Also, clarify contributing and licensing.

Signed-off-by: Tomi Sarvela <tomi.p.sarvela@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>