Created HOWITWORKS; cleanup of README

Addresses a request from @chrisboulton in GitHub issue #149

* Slight grammar cleanup and content update in README.md
* Mention of HOWITWORKS.md in README.md, referring those who want to know more that direction
* Expanded and slightly cleaner version of a comment made in #149 that prompted this commit/PR
  was placed in HOWITWORKS.md

Signed-off-by: Daniel Hunsaker <danhunsaker@gmail.com>