Make initial backend structure

[aahnik]

create initial project structure to start backend work

business logic

• [x] simple register and login routes. (no extra layer of security/email verification)
• [x] issue jwt tokens upon login/register, and verify them on each request (from Header: Bearer Token)
• [x] endpoint to upload files to backend
• [x] decorator(nest js guard) for role based access
• [x] decorator for making some routes public, by default all routes are protected

project structure

• [x] setup nest js, connected with mongo db
• [x] setup developer tools such as eslint and prettier
• [x] docs/References.md to keep track of relevant articles and docs pages