Update the readme file to add instructions for getting and adding API keys, add .env.local.example file

Spent days setting this project up, and finally got it running. Added an .env.local.example file where one can add the API keys. Also included the instructions to obtain the API keys (which isn't really obvious) and coverage to requirements.txt Used some information from here https://gist.github.com/hitesh1157/171b6f5aa85469ffd9a2a620c4f44073