Create a user-guide/help pages

[yGuy]

Explain how to work with the tool - how to search, navigate, and select (multiple!) elements, then how to load and remove related items, etc.
Explain how to use the detail panels, etc.
Create screen-casts, screen-shots, and a description.
Include it in the UI!

[Jiros]

I've added a draft guidance document and an overview of the interface diagram -
https://github.com/covidgraph/visual-graph-explorer/blob/master/docs/vge-guidance.md

I still need to:

• Add a link to the most recent data model
• Identify a few real world examples and either write these up as step by step guides or do a screencast
• Add more screenshots.

Happy for any feedback or to adjust the terminology I have adopted here to match any other expectations.