fixed missing end and added gitingore

.gitignore

@@ -0,0 +1 @@
+*.swp

map_layout.lua

@@ -12,5 +12,5 @@ local function chunk_modification(event)
 			surface.set_tiles(tiles)
 		end
 	end
-
-Event.register(defines.events.on_chunk_generated, chunk_modification)
+end
+Event.register(defines.events.on_chunk_generated, chunk_modification)