update links

docs/source/developer/adding_content.md

@@ -4,7 +4,7 @@ As an example: Add a leaflet viewer plugin for geoJSON files.
 
 - Go to npm: search for [leaflet](https://www.npmjs.com/package/leaflet) (success!).
 - Go to `jupyterlab` top level source directory: `jlpm add leaflet`.  This adds the file to the `dependencies` in `package.json`.
-- Next we see if there is a typing declaration for leaflet: 
+- Next we see if there is a typing declaration for leaflet:
 `jlpm add --dev @types/leaflet`.  Success!
 - If there are no typings, we must create our own.  An example typings file that exports functions is [ansi_up](https://github.com/jupyterlab/jupyterlab/blob/master/packages/rendermime/typings/ansi_up/ansi_up.d.ts).  An example with a class is [xterm](https://github.com/jupyterlab/jupyterlab/blob/master/packages/terminal/typings/xterm/xterm.d.ts).
 - Add a reference to the new library in `src/typings.d.ts`.
@@ -12,8 +12,8 @@ As an example: Add a leaflet viewer plugin for geoJSON files.
 - Add  `index.ts` and `plugin.ts` files.
 - If creating CSS, import them in `src/default-themes/index.css`.
 - The `index.ts` file should have the core logic for the plugin.  In
-this case, it should create a widget and widget factory for rendering geojson 
-files (see [Documents](documents.md)).
+this case, it should create a widget and widget factory for rendering geojson
+files (see [Documents](documents.html)).
 - The `plugin.ts` file should create the extension and add the content
 to the application.  In this case registering the widget factory using
 the document registry.

docs/source/developer/documents.md

@@ -58,7 +58,7 @@ to each widget or observe the widget and/or its context.
 
 Intended to be used in a "Create New" dialog, providing a list of known file types.
 
-### [File Creators](http://jupyterlab.github.io/jupyterlab/classes/_docregistry_src_registry_.documentregistry.html#addcreator)
+### [File Creators](http://jupyterlab.github.io/jupyterlab/classes/_docregistry_src_registry_.documentregistry.html)
 
 Intended for create quick launch file creators.
 

docs/source/developer/extension_dev.md

@@ -188,7 +188,7 @@ for an example.  Ensure that the theme files are included in the
 an `embed.css` file that can be consumed outside of a JupyterLab application.
 
 To quickly create a theme based on the JupyterLab Light Theme, follow the
-instructions in the [contributing guide](https://github.com/jupyterlab/jupyterlab/blob/master/CONTRIBUTING.md#setting-up-a-development-environment)
+instructions in the [contributing guide](CONTRIBUTING.html#setting-up-a-development-environment)
 and then run `jlpm run create:theme` from the repository root directory.
 Once you select a name, title and a description, a new theme folder will be
 created  in the current directory.  You can move that new folder to a location
@@ -199,7 +199,7 @@ The theme extension is installed the same as a regular extension (see
 
 ## Standard (General-Purpose) Extensions
 See the example,
-[How to Extend the Notebook Plugin](./notebook.md#how-to-extend-the-notebook-plugin). Notice that the mime
+[How to Extend the Notebook Plugin](./notebook.html#how-to-extend-the-notebook-plugin). Notice that the mime
 renderer and themes extensions above use a limited, simplified interface to
 JupyterLab's extension system. Modifying the notebook plugin requires the full,
 general-purpose interface to the extension system.
@@ -282,5 +282,3 @@ this.node.addEventListener('contextmenu', this);
 case 'contextmenu':
   event.stopPropagation();
 ```
-
-

docs/source/developer/virtualdom.md

@@ -11,7 +11,7 @@ In situations where these feature are needed, we recommend using Phosphor's
 `Widget` class directly.
 
 The idea of virtual DOM rendering, which became popular in the
-[React](https://facebook.github.io/react/) community, is a very elegant and
+[React](https://nodejs.org/en/) community, is a very elegant and
 efficient way of rendering and updating DOM content in response to model/state
 changes.
 
@@ -21,4 +21,4 @@ needed.
 
 An example of using React with Phosphor can be found in the
 [launcher](https://github.com/jupyterlab/jupyterlab/blob/master/packages/launcher/src/index.tsx)
-of JupyterLab.
+of JupyterLab.

docs/source/developer/xkcd_extension_tutorial.md

@@ -165,7 +165,7 @@ Return to the browser.  Open the JavaScript console in the JupyterLab tab by fol
 * [Accessing the DevTools in Google Chrome](https://developer.chrome.com/devtools#access)
 * [Opening the Web Console in Firefox](https://developer.mozilla.org/en-US/docs/Tools/Web_Console/Opening_the_Web_Console)
 
-You should see a message that says `JupyterLab extension jupyterlab_xkcd is activated!` in the console. If you do, congrats, you're ready to start modifying the the extension! If not, go back, make sure you didn't miss a step, and [reach out](https://github.com/jupyterlab/jupyterlab#getting-help) if you're stuck.
+You should see a message that says `JupyterLab extension jupyterlab_xkcd is activated!` in the console. If you do, congrats, you're ready to start modifying the the extension! If not, go back, make sure you didn't miss a step, and [reach out](README.html#getting-help) if you're stuck.
 
 Note: Leave the terminal running the `jupyter lab --watch` command open.
 

docs/source/user/extensions.md

@@ -15,7 +15,7 @@ If you use ``conda``, you can get it with:
 conda -c conda-forge install nodejs
 ```
 
-If you use [Homebrew](http://brew.sh/) on Mac OS X:
+If you use [Homebrew](https://brew.sh/) on Mac OS X:
 
 ```bash
 brew install node