The .rar file only includes the map PNGs as exported from Dungeon Scrawl, for use with VTTs and stuff like that. The module itself with the room key comes bundled at the end of the of the full game's PDF (just like the starter dungeon from Mörk Borg does, I was trying to mimic that 😅)
Now that you mention it, I should probably edit the images to include the map legend too.