Add an interactive REPL-like or Monaco (IDE) to website under Ganache documentation

[davidmurdoch]

Ganache can run in the browser, and while we will have Interactive Docs Soon:tm: , it's be useful to also have a playground somewhere within the ganache docs that isn't focused on being reference documentation, but acts as a quick demonstration of how to use ganache and what it does.

Perhaps a "tutorial mode", al la, mongodb's old try.mongodb.com (see https://www.mongodb.com/blog/post/the-mongodb-web-shell ) could come about from this. I think a ganache tutorial CLI command would be really cool.