DOC: improving readability and auth instructions #33

[sabinevidal]

DOC: Improving wording for instructions

• Added route for where allowed_origins is, as like will take to GitHub, whereas devs might be working alongside on their local.
• Added '(you only have to run this the first time if api/model is empty)' for downloading ML model instructions, to make this more clear instead of just 'one time'. Also so devs know where to look for the files. And covers for edge case where someone may change their git branch and don't stash the /model file which then may be lost, which could cause confusion.

DOC: improving auth section

• Made it clearer that the dev needs to also create the .env folder, not just update the allowed_origins, as without the .env folder the site threw a 500 error when trying to check a word. Not sure if this is a feature or a bug.

  File "api.py", line 69, in checkHeaders
  tokens = json.loads(os.getenv('TOKEN_KEYS')) #this will throw an error upon request if no token keys are present in the environment at all
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/json/__init__.py", line 341, in loads
  raise TypeError(f'the JSON object must be str, bytes or bytearray, '
  TypeError: the JSON object must be str, bytes or bytearray, not NoneType

• Included a Note under configuration explaining what errors might arise if authorisation hasn't been set up properly.
• Made Making Request with Authorization Tokens a level 2 header to differentiate it from Running locally.
• Added more information to 'Making Request with Authorization Tokens'

[sabinevidal]

I experimented with different variations of the auth setup, ie with/out localhost in allowed_origins, and with/out the .env file and the TOKEN_KEYS. Having both fixed the 500 error when trying to test the requests. However, I still encountered a 403 error when submitting on the /detect endpoint on my locally run site. I received the json results when testing the curl request though.