📚 Documentation

The Developer Guide (see sidebar on https://scitools-iris.readthedocs.io/en/latest/) is in need of an overhaul, including:

• General structure of the contents
• New page for detailing how to get started developing
• New page for more info on how to run the tests
• Finalise the graphics tests documentation
• Review and update the git instructions

This is a parent issue that may resolve: 

1. Developer guide - image testing #2170. Developer guide - image testing
2. Complete Graphics Testing Documentation #2331. Complete Graphics Testing Documentation
3. Pull-request checklist needs a revamp #3453. Pull-request checklist needs a revamp
4. Documenting the addition of a gallery entry #314. Documenting the addition of a gallery entry
5. Improve the docs around adding/extending/replacing a graphics test #2902. Improve the docs around adding/extending/replacing a graphics test