General Documentation

[maxmwang]

Add documentation on new GraphQL spec, overall file structure, etc. for frontned's use during testing and for future backend members. Documentation will likely be in Github Wiki.

More specifically, details including but not limited to:

• description of each directory within repository
• rationale behind design decisions
• runbooks on getting started / common issues
• links to issues/documentation/other references

The scope should include our infrastructure up to our application backend.