reorg

tutorial/extensions.md

@@ -9,24 +9,7 @@ to the application and are covered in the Documents tutorial.
 A JupyterLab application is comprised of Services and Extensions, as well as a 
 core [Application](https://github.com/phosphorjs/phosphide/blob/master/src/core/application.ts) object.
 
-## [Services](https://github.com/phosphorjs/phosphide/blob/master/src/core/serviceregistry.ts) 
-A service provider is used by extensions to add functionality to the
-application. 
-- Service providers can require other services.
-- Services are activated when they are needed by other services or extensions.
-- An example service is the [document registry](https://github.com/jupyter/jupyterlab/blob/master/src/docregistry/plugin.ts), which is used by extensions
-to add functionality around widgets backed by files.
-
-## [Extensions](https://github.com/phosphorjs/phosphide/blob/master/src/core/extensionregistry.ts#L19) 
-Extensions use the Application object and optionally other services to provide 
-functionality to the application. 
-- Extensions provided to the application are activated immediately. 
-- An example extension is the [editor widget](https://github.com/jupyter/jupyterlab/blob/master/src/editorwidget/plugin.ts), which registers an 
-editor widget factory with the Document Registry.
-- Extensions are activated explicitly through the Application [instance](https://github.com/phosphorjs/phosphide/blob/master/src/core/application.ts#L71).
-
-- A full example is contained [here](https://github.com/jupyter/jupyterlab/tree/master/examples/lab).
-
+A full example is contained [here](https://github.com/jupyter/jupyterlab/tree/master/examples/lab).
 
 The default providers in the JupyterLab application include:
 - Services - An application-specific interface to `jupyter-js-services`.
@@ -45,3 +28,15 @@ The default extensions in the application include:
 - Editor - Add a widget factory for displaying editable source files.
 - Console - Adds the ability to launch Jupyter Console instances for
 interactive kernel console sessions.
+
+## [Services](https://github.com/phosphorjs/phosphide/blob/master/src/core/serviceregistry.ts) 
+A service provider is used by extensions to add functionality to the
+application. 
+- Service providers can require other services.
+- Services are activated when they are needed by other services or extensions.
+
+## [Extensions](https://github.com/phosphorjs/phosphide/blob/master/src/core/extensionregistry.ts#L19) 
+Extensions use the Application object and optionally other services to provide 
+functionality to the application. 
+- Extensions provided to the application are activated immediately. 
+- Extensions are activated explicitly through the Application [instance](https://github.com/phosphorjs/phosphide/blob/master/src/core/application.ts#L71).