Access rendered HTML

[scarroll32]

Provide a means to extract rendered HTML for storage in a backend. This will allow a rendered Typewriter document to be used in an application where no edits are possible. ie: One page is edit and the document is authored, while on another page the rendered document is viewed.

[jacwright]

While not documented yet, view.getHTML() and view.setHTML(htmlString) are available. These allow you to get the HTML of the contents in a performant way without the decorators which may exist in the actual HTML.

getHTML actually could work without being in the browser, but setHTML leans on the browser to convert the text to DOM then converts it to a Delta. If we can change this without adding significantly to the codebase it would be nice.