I have been learning JME 3.1 by navigating to menu “Help” → “Browse Help Locally”. I found some links that are broken at the moment. I also found that by navigating to “Help” → “Browse Help Online” (http://jmonkeyengine.org/wiki/doku.php/jme3), such navigation would give you “404 page not found”.
I think the local help will stay broken forever, I am afraid as long as no one takes the time to fix it.
The problem is that the help used to download the old wiki in a special mode (I think in a printable version).
With that code being broken it is not really possible to update the help anymore. Of course everbody is free to have a look at How it was exactly done back then and then work together with the awesome wiki guys, maybe it is possible to write a small parser for that.
Edit: For example this <a href="http://jmonkeyengine.org/wiki/doku.php/sdk:welcome:3_0rc3?do=export_xhtmlbody">