Create project documentation

[lachieh]

Since we've split out from the main repo, we need some docs in here! At a minimum, would should get a README.md in here, but it'd be good to make sure the CONTRIBUTING.md reflects the fact that this repo includes both apps/packages, as well as TS examples. It would also be great to have make use of the issue template forms.

• Create top-level README.md
• Update CONTRIBUTING.md to reflect repo inclusions
• Add .github/ISSUE_TEMPLATE