adding map properties to documentation

* screenshot of the result of the map properties
* first try at documenting map properties

docs/maps/wa-maps.md

@@ -92,3 +92,19 @@ You can add properties either on individual tiles of a tileset OR on a complete
 If you put a property on a layer, it will be triggered if your Woka walks on any tile of the layer.
 
 The exception is the "collides" property that can only be set on tiles, but not on a complete layer.
+
+## Insert helpful information in your map
+
+By setting properties on the map itself, you can help visitors know more about the creators of the map.
+
+The following *map* properties are supported:
+* `mapName` (string)
+* `mapDescription` (string)
+* `mapCopyright` (string)
+
+And *each tileset* can also have a property called `tilesetCopyright` (string). 
+
+Resulting in a "credit" page in the menu looking like this:
+
+![](images/mapProperties.png){.document-img}
+