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>
Merge pull request #154 from danhunsaker/readme/howitworks

Created HOWITWORKS; cleanup of README