[#4] [#5] Improve usability of website docs. Simplify README.
* Reorg asset layout
* Reduce code font size on mobile -- less wrapping
* Update website copy, improve content for max impact
* Make substantial improvements to flow of user documentation.
* Add nudge for viewer to go star on github.
* Clarify how to try examples out.
* Improve styles for notes.
* Refer viewer to the website if they need more examples or try-b4-u-buy