WikiBookmarks is a MediaWiki extension which lets you to manage shared bookmark lists inside a Wiki article. The extension is written by Vitaliy Filippov and is distributed under the terms of GNU GPL license version 3 or later. Also, here is a link to extension homepage.
You always can find a fresh version of the WikiBookmarks documentation on the Special:Bookmarks page. Actually, you've already found it :-).
WikiBookmarks are used in the form of a tiny bookmarklet (what is a bookmarklet?). To install such a bookmarklet in your browser, you need to enter the title of Wiki Article which you want to maintain as your bookmark list, click Make bookmarklet and drag-and-drop displayed link onto your browser's panel or add it into your browser's bookmarks.