Add extractor and builder

Tested and working

snippets/disable-selection.md

@@ -5,23 +5,17 @@ tags: interactivity,intermediate
 
 Makes the content unselectable.
 
-#### HTML
-
 ```html
 <p>You can select me.</p>
 <p class="unselectable">You can't select me!</p>
 ```
 
-#### CSS
-
 ```css
 .unselectable {
   user-select: none;
 }
 ```
 
-#### Demo
-
 #### Explanation
 
 `user-select: none` specifies that the text cannot be selected.