Readme revamp

This PR adds the following info to the readme:

* Basic about section for the project
   * Adds a nifty gif to show a basic walkthrough of the app
   * Describes who made the app and what it does
   * Cautions that the app is still early-stage dev
* Adds install pre-requisites with links to CFA HowTos
* Adds Local Install instructions
* Adds Heroku deploy instructions
* Adds basic contribution guidelines (submit PR/submit issue)
* Adds more detailed contributor info (names of who made this w/ contact info)
* Adds copyright/license for project

cc @amymok ... maybe we could have somebody test the local deploy/heroku deploy instructions to make sure I didn't leave anything out, or describe anything in a weird way?