Add README and Templates

[titaniumbones]

Make sure this repo has the following files:

• [ ] Readme README.md
  • [ ] Repo Badges for: Github Project, Slack, License
  • [ ] 1-3 sentence description of repository contents
  • [ ] Getting Involved section
  • [ ] Development section
• [x] License -- LICENSE
• [x] Contributing Guidelines (minimal and pointing to org-wide) .github/CONTRIBUTING.md
• [x] Issue Template -- .github/ISSUE_TEMPLATE.md
• [ ] GitHub Description from 1-3 sentence readme blurb

This issue forms part of a project-wide meta-issue

[titaniumbones]

Larely addressed in #5 but waiting for rewrite #8 to proceed before merging, as the status of this repo is in flux. Removing doc-sprint label & will resolve datatogether/datatogether#37 without closing this issue.