fix: revise the wording

Signed-off-by: Shunsuke Miura <[email protected]>

docs/design/autoware-architecture/perception/index.md

@@ -47,23 +47,21 @@ The Perception Component consists of the following sub-components:
   - Bicycles
   - Motorcycles
   - Animals
-  - Traffic Cones
-  - Fallen Objects, Flying Objects, etc: Items such as cardboard, drums, wood, etc., either falling or airborne.
+  - Traffic cones
+  - Road debris: Items such as cardboard, oil drums, trash cans, wood, etc., either dropped on the road or floating in the air
 - **Obstacle Segmentation**: Identifies point clouds originating from obstacles, including both dynamic objects and static obstacles that requires the ego vehicle either steer clear of them or come to a stop in front of the obstacles.
   - This includes:
-    - all dynamic objects (as listed above)
-    - curbs/bollards
-    - barriers
-    - trees
-    - walls/buildings
-    - etc
+    - All dynamic objects (as listed above)
+    - Curbs/Bollards
+    - Barriers
+    - Trees
+    - Walls/Buildings
   - This does not include:
-    - grass
-    - water splashes
-    - smoke/vapor
-    - newspapers
-    - plastic bags
-    - etc
+    - Grass
+    - Water splashes
+    - Smoke/Vapor
+    - Newspapers
+    - Plastic bags
 - **Occupancy Grid Map**: Detects blind spots (areas where no information is available and where dynamic objects may jump out).
 - **Traffic Light Recognition**: Recognizes the colors of traffic lights and the directions of arrow signals.