UI docs: Remove dead link from example (#8551)

UI docs: Remove dead link from example

lib/ui/README.md

@@ -6,20 +6,20 @@ You can configure it by providing a provider API.
 
 ## Table of Contents
 
--   [Usage](#usage)
--   [API](#api)
-    -   [.setOptions()](#setoptions)
--   [.setStories()](#setstories)
--   [.onStory()](#onstory)
--   [Hacking Guide](#hacking-guide)
-    -   [The App](#the-app)
-    -   [Changing UI](#changing-ui)
-    -   [Mounting](#mounting)
-    -   [App Context](#app-context)
-    -   [Actions](#actions)
-    -   [Core API](#core-api)
-    -   [Keyboard Shortcuts](#keyboard-shortcuts)
-    -   [URL Changes](#url-changes)
+- [Usage](#usage)
+- [API](#api)
+  - [.setOptions()](#setoptions)
+- [.setStories()](#setstories)
+- [.onStory()](#onstory)
+- [Hacking Guide](#hacking-guide)
+  - [The App](#the-app)
+  - [Changing UI](#changing-ui)
+  - [Mounting](#mounting)
+  - [App Context](#app-context)
+  - [Actions](#actions)
+  - [Core API](#core-api)
+  - [Keyboard Shortcuts](#keyboard-shortcuts)
+  - [URL Changes](#url-changes)
 
 ## Usage
 
@@ -41,9 +41,7 @@ export default class MyProvider extends Provider {
   }
 
   renderPreview() {
-    return (
-      <p>This is the Preview</p>
-    );
+    return <p>This is the Preview</p>;
   }
 
   handleAPI(api) {
@@ -63,8 +61,6 @@ const roolEl = document.getElementById('root');
 renderStorybookUI(roolEl, new Provider());
 ```
 
-> **See the [example](./example) app for a complete example.**
-
 ## API
 
 ### .setOptions()
@@ -79,7 +75,7 @@ class ReactProvider extends Provider {
       // https://github.com/storybookjs/storybook/tree/master/addons/options#getting-started
     });
   }
-};
+}
 ```
 
 ## .setStories()
@@ -94,13 +90,13 @@ class ReactProvider extends Provider {
     api.setStories([
       {
         kind: 'Component 1',
-        stories: ['State 1', 'State 2']
+        stories: ['State 1', 'State 2'],
       },
 
       {
         kind: 'Component 2',
-        stories: ['State a', 'State b']
-      }
+        stories: ['State a', 'State b'],
+      },
     ]);
   }
 }
@@ -116,7 +112,7 @@ import { Provider } from '@storybook/ui';
 class ReactProvider extends Provider {
   handleAPI(api) {
     api.onStory((kind, story) => {
-        this.globalState.emit('change', kind, story);
+      this.globalState.emit('change', kind, story);
     });
   }
 }
@@ -178,6 +174,7 @@ TODO: state we use reach/router customized to query params
 ### Story Order
 
 Stories are sorted in the order in which they were imported. This can be overridden by adding storySort to the Parameters for the stories in `.storybook/config.js`:
+
 ```js
 addParameters({
   options: {