Have to replace state instead of adding.
This editor is called by visiting /entries/new
When the Etch is created we want to replace the URL instead of pushing a new one to
the state. If the user navigates back they should go back to the entry list. If we
added a state it may seem confusing if they navigate backwards. Consider,
User opens entry list
Creates a new entry by opening /entries/new, default title is 12/05/2019
User creates a few etches
Entry is created and we add URL /entries/A4nJpaSAAb0 to the state
User navigates backwards and it creates a new entry with title 12/05/2019.
It may seem like their etches were lost by navigating backwards.
Fixes #149.
Something interesting about this change.