Board Thread:Support Requests - Getting Technical/@comment-6475116-20130829012241/@comment-5175866-20130904220105

there's no extentsion that does it. All wikis on Wikia do it by default, its a core software featured included in the Wikia software. If you want to have this for a plain mediawiki wiki outside of wikia that doesn't include Wikia software, than let me know and I can try to help you find the page for this in Wikia's Github directory.