Update Design Doc: `level` tool

Design-Doc%3A-%60level%60-tool.md

@@ -95,12 +95,4 @@ For (number of component instances):
    * 2 bytes: Index of the component definition (from component definitions - not the ID! but the index)
    For (number of 16-bit properties in the component as determined from its entry in "Component Definitions"):
       * 2 bytes: Value of the associated field (order per configuration TOML as mentioned above).
-```
-
-### Map Data
-```
-For plane B, then plane A:
-   For (total tiles height):
-      For (total tiles width):
-         2 bytes: Tilemap ID (0 = No Tile, otherwise offset by 1 in the tilemap)
 ```