Add Docs

[GDYendell]

• [x] #318
• [x] Top commit to be removed once tested
• [ ] Update odin_data/client.py and docs on using client Will make separate PR

Fixes #218

[GDYendell]

I think this is ready now. It is definitely not complete, but having this framework in place so that it is easy to add documentation as we go along will be really useful.

I have removed the use of the client app and will make a separate PR. The old frame_receiver_client / new odin_data_client is quite different from the API I had in my version and wrote the docs for, so I would like to make some changes and that requires further discussion.

[GDYendell]

The docs are visible here. Note the docs in the URL is not static, it is just the branch name. So, when merged there will be a https://odin-detector.github.io/odin-data/master/index.html, which https://odin-detector.github.io/odin-data will redirect to. There is a dropdown selector for each active branch so the docs can be tested before merging PRs.