Update qbeast-spark documentation for docs site launch

[spigelli]

We need to rewrite spark documentation for the latest version:

• Update documentation so that pages are consistent with these guidelines so that pages will render well on the website
• Update documentation under the assumption of a platform offering rather than an open source software or internal notes, we can optionally keep internal pages with some prefix/suffix scheme that @spigelli can account for in the content loader for the site

Qbeast spark should focus around usage and features that the customer will need