Refactored Editor Routing

- Moved `new` route into `editor` resource (`editor.new`)
- Moved the current editor controller, view, and route to `editor.edit`
- Added `editor.index`, which automatically transitions into `editor.new`
- Moved controllers, views, templates, and routes to match new router config. Also changed links to `editor` into `editor.new` and `editor.edit` as appropriate.