add dependencies and environment variable sections
instructions for creating and seeding the database
Add instructions for starting application.
Clean up explanation of where data comes from
hard wrap and condense environment instruction
fix chained rake command
fix link, heroku -> devbootcamp

this closes #18
Move link reference to new line.

Wrap line harder.
Describe which data is primary, secondary, or derived
Whitespace and line wrapping to make this easier to review on github
http -> https
Merge pull request #16 from Devbootcamp/better-readme

Many config, setup, and run instructions are added to readme.