update introduction

Signed-off-by: ismetatabay <[email protected]>

docs/how-to-guides/integrating-autoware/creating-maps/pointcloud-map-preprocessing/index.md

@@ -2,10 +2,14 @@
 
 ## Overview
 
-When your created point cloud map is either too dense or too large (i.e., exceeding 300 MB),
-you may want to downsample it for improved computational and memory efficiency.
-Also, you can consider using dynamic map loading with partial loading,
-please check [map_loader package](https://github.com/autowarefoundation/autoware.universe/tree/main/map/map_loader) for more information.
+Pointcloud map used in Autoware should be downsampled with a voxel size of around 0.1 to 0.2 meters
+to minimize the computational costs and memory bandwidth load.
+Also,
+you may consider
+using dynamic map loading with partial loading
+if your map is still too large to handle as a single file
+(~2 GB in PCD size).
+Please check [map_loader package](https://github.com/autowarefoundation/autoware.universe/tree/main/map/map_loader) for more information.
 
 At tutorial_vehicle implementation we will use the whole map,
 so we will downsample it with using [CloudCompare](https://www.cloudcompare.org/main.html).