Fix Fall-through Tiles on Experimental maps.

[zicklag]

For some reason the Deno script, migrate-maps.ts, that we used to port the maps from the old version of Jumpy didn't correctly pick up the fall-through tile info for some of the experimental maps.

We need to fix the fall-through tiles to work on the experimental maps.

There are two ways we could go about this:

• Manually edit the YAML/JSON files for the maps in question to add the jump_through field to true for the jump-through tiles.
• Fix and re-run the script for those maps
  • Note: If we update the script, we need to take into account that we modified the background layer metadata format, and we'll need to incorporate those changes into the script.

[zicklag]

This has been fixed in #651 with the re-implementation of the map editor!