Correct migration of old documentation

docs/snippet-extend-navigation.md

@@ -1,4 +1,27 @@
-### Extend Navigation
+### Snippet: Extend Navigation
 
-[Complete
-source](https://bitbucket.org/sdorra/scm-code-snippets/src/tip/001-extend-navigation "wikilink")
+```javascript
+// add login callback
+loginCallbacks.push(function(){
+  // get the main navigation
+  var navPanel = Ext.getCmp('navigationPanel');
+  // insert the new navigation section at the
+  // second position
+  navPanel.insertSection(1, {
+    title: 'My Links',
+    links: [{
+      label: 'Link 1',
+      fn: function(){
+        alert('Link 1');
+      }
+    },{
+      label: 'Link 2',
+      fn: function(){
+        alert('Link 2');
+      }
+    }]
+  });
+});
+```
+
+[Complete source](https://bitbucket.org/sdorra/scm-code-snippets/src/tip/001-extend-navigation)