Docs Update: Chat Widget

[stephherbers]

Here is the desired location: https://docs.openchatstudio.com/how-to/embed/#test-the-chatbot

Add more information on how do participant data and session data relate to the chat widget?
E.g. if someone refreshes their web page, will the chat widget automatically start a new session? And is there a way for the chat widget to recognize returning users (and therefore have access to participant data for that user)?