Okay, I figured it out by browsing about. You need to make a new folder for your map, name your map when you save it as level_mapname, and make to XML files:
info.xml:
<info>
<name>Script test level</name>
<description></description>
<lives>10</lives>
</info>
and
levels.xml:
<levels start="1">
<act name="lvl.act1">
<level id="1" res="test_puzzle.xml" name="Puzzle test" />
</act>
</levels>