Development Environment Docs & Improvements

[sneakers-the-rat]

Redo: https://github.com/openjournals/joss/pull/1356 without model annotations

This PR:

• Add more docs on setting up development environment
• Don't validate review repository URLs on creating Paper objects if in the development environment so that it's possible to create fake papers/reviews for testing
• Add a "paper" type to dev environment config
• Create some basic seed data for dev environment.

Questions:

• is the readme the right place? i also notice https://github.com/openjournals/joss/blob/main/docs/installing.md which seems more like if you were to want to do a secondary deployment for a different journal, but just checking
• I only added enough seed data to be able to test https://github.com/openjournals/joss/pull/1357 , so eg. I didn't put a full paper body in there. is there some way to use the factory classes in the spec directory like https://github.com/openjournals/joss/blob/main/spec/factories/papers_factory.rb in db/seeds.rb? I don't know enough about ruby environments, wasn't sure how to call that, but that would probably be preferable to use those, so then we could create a full seed dataset with all the types of models from the same sources that the tests use. If that is possible/desirable, i can follow on with another PR for that, seems like it would be a nice thing to do both for people checking this out if they wanted to do a secondary deployment and also for quick debugging purposes.