How is the API documented in jQuery in order to provide intellisense?.

How is the API documented in jQuery in order to provide intellisense?.

Hi,
 
Have the below query. Please help me to understand. We have javadoc way of providing documentation for java class and methods. Similarly, What's the standard way of documenting javascript?.
 
I added the following js file and in my html made reference to the script
<script type="text/javascript" src="js/jquery-1.8.3.js"></script>
 
<script type="text/javascript">
$(document).ready(function() {
             $(selector).   // It immediately shows me all the methods possible
     });
</script>     

 
Also, the method details like Summary, Parameters, Returns, Code Example etc., comes up.
 
I searched in the jquery-1.8.3.js and don't see them there.
 
How and where is this documentation coming from?. 
 
Please advise.
 
Thanks & Regards,
Ramesh S