Note that this way, what gets created isn't usable as an add-on, but rather as a zip that needs to be manually dumped in a levels directory. Add-ons use a different directory structure.
The built-in level editor takes care of creating the info file as soon as you create a levelset/world there.
manuel {l Wrote}:If you don't want to see your world in-game, change hide-from-contribs to #t. (Don't know why this option is in there, but okay...)
Well, world1 (Icy Island) is hidden from contribs.