Escape HTML in code examples

Fixes documentation generation for code like the following:

```javascript
/**                                                                             
 * @example                                                                     
 * <caption>Loop something</caption>                                                  
 * for(var i = 0; i<n; i++){                                                  
 *                                                                              
 * }                                                                            
 */                                                                             
function doSomething(){}
```