Tidy up the repo folder structure

[JohnShiuMK]

Simon:

By the end of the week, along with all your other work, I'd like to see:

• a clear GitHub directory structure. #98
• Make sure everyone's branches are pushed and pulled into main or dev so that they are accessible to the team, and helpful for pushing the project forward.
• Make sure elements of the project are being properly tested.
• a good clear README (it doesn't have to be complete, but should have the key elements of a good README in place, see: https://github.com/earthcube/EC_Repository_Template/blob/master/TemplateREADME.md or similar) #97
• A skeleton of your report with two or three figure concepts. These may be graph ideas, plotting some of your data, overviews of your workflow, or some other conceptual figure. I just want you to think about what you are going to write, and how you want to showcase the work you've done.

[SoloSynth1]

• a clear GitHub directory structure.

@JohnShiuMK I'm thinking about putting content inside src/gpt_4/ to elsewhere. Do you have any suggestions on this?

[SoloSynth1]

Closing this issue as the sub-issues are tracked by #99 instead.