Outdated link on performance/read-the-source

[arthurvr]

Looks like we're linking to an outdated version of the jQuery source in there. The shorturl links to jquery-latest, which still is on 1.11.1. See https://github.com/jquery/learn.jquery.com/blob/master/page/performance/read-the-source.md

[arthurvr]

IMHO we could change this sentence:

Bookmark http://bit.ly/jqsource and refer to it often.

to

Bookmark the CDN, and refer to it often.

Having a link is unmaintainable.