Hi, the link in the codex page for the Timeline plugin which now points to the larger project's wiki should be changed to point to the more recent simile-widgets.org Timeline homepage - http://www.simile-widgets.org/wiki/Timeline
The wiki page hasn't been updated for a while, and is going to go away, according to the new page listed above.
I'm going to go ahead and update that link, but the next time you notice a problem or just something that could be better about the documentation, remember that Omeka's documentation is a wiki, so you can create an account and edit it yourself!
The codex runs on MediaWiki, the same software that powers Wikipedia, so if you know how to edit there, you know how to edit here.
Thanks - I didn't realize that about the documentation. It must run on a separate login from the forums.