Clicking on the back button after creating a new document will create another document

[jimpick]

Because the new root url redirects to a new document, going back will create a new document.

We probably need to manage history better.

Perhaps we shouldn't create a new document without user interaction, as it is a bit surprising.

[parkan]

the simplest solution here is to use history.replaceState so there's no "back" history entry to go back to

[parkan]

reworking history handling will also affect #311