Perception: modify Perception README (ApolloAuto#12630)

modules/perception/README.md

@@ -7,10 +7,13 @@ component named Detection component.
 Apollo 6.0 Perception has following new features:
 
  * **PointPillars Obstacle Detection**
+ * **Online PointPillars Model Training Service**
 
 The perception module incorporates the capability of using multiple cameras, radars (front and rear) and LiDARs to recognize obstacles and fuse their individual tracks to obtain a final track list.
 The obstacle sub-module detects, classifies and tracks obstacles.
 This sub-module also predicts obstacle motion and position information (e.g., heading and velocity).
+Besides, we provide an online service for training PointPillars models using your own data
+(https://github.com/ApolloAuto/apollo/blob/master/docs/Apollo_Fuel/Perception_Lidar_Model_Training/README.md).
 For lane line, we construct lane instances by postprocessing lane parsing pixels and calculate the lane relative location to the ego-vehicle (L0, L1, R0, R1, etc.).
 
 ***\**Note: Camera obstacle detection is not available so far due to the in-process model upgrading.