[Update] update our LiDAR-camera calibration method FAST-Calib.

Author: xuankuzcr

README.md

@@ -42,8 +42,8 @@ Our associate dataset [**FAST-LIVO2-Dataset**](https://connecthkuhk-my.sharepoin
 ### MARS-LVIG dataset
 [**MARS-LVIG dataset**](https://mars.hku.hk/dataset.html)：A multi-sensor aerial robots SLAM dataset for LiDAR-visual-inertial-GNSS fusion
 
-### 1.5 Our calibration method
-Stay tuned...
+### 1.5 Our LiDAR-camera calibration method
+The [**FAST-Calib**](https://github.com/hku-mars/FAST-Calib) toolkit is recommended. Its output extrinsic parameters can be directly filled into the YAML file. 
 
 ## 2. Prerequisited