Incorrect signature of .ready() handler

[goffioul]

The reference documentation for .ready() handler does not specify any argument for the signature of the handler. However, the jQuery object is actually provided, which is quickly explained later in the section Aliasing the jQuery Object. This can be easily missed (like I did) and lead to writing incorrect code (like making jQuery triggering the ready event endlessly).

[mgol]

Would you like to submit a PR with proposed changes? All the individual pages are located in their own files in https://github.com/jquery/api.jquery.com/tree/master/entries.