Moved the view that renders JSON returned when creating a new folder to the views/folders folder.

This is the natural place for this file to be, as it's a view that is only rendered by the FoldersController#create method.
Renamed _new_folder.json.erb to create.json.erb

This is the natural name for this view, as it renders the JSON returned by FoldersController#create. The leading underscore is not necessary: this is a full view, not a partial.
Moved the view that renders JSON returned when updating a folder to the views/folders folder.

This is the natural place for this file to be, as it's a view that is only rendered by the FoldersController#update method.
Renamed _update_folder.json.erb to update.json.erb

This is the natural name for this view, as it renders the JSON returned by FoldersController#update. The leading underscore is not necessary: this is a full view, not a partial.