update

README.md

@@ -13,20 +13,16 @@
 ```bash
 cd /workspace
 colcon build --symlink-install
-source /opt/ros/humble/setup.bash
-source install/setup.bash
 ```
 
 ### 注意事项
 
-为了方便，写入 `~/.bashrc`：
+每一个终端执行前建议：
 
 ```bash
-echo 'source /opt/ros/humble/setup.bash' >> ~/.bashrc
-echo 'source /workspace/install/setup.bash' >> ~/.bashrc
-echo 'export TURTLEBOT3_MODEL=burger' >> ~/.bashrc
-echo 'export NAV2_MAP_PATH=/workspace/src/turtlebot3_simulations/turtlebot3_gazebo/map/office_map.yaml' >> ~/.bashrc
-source ~/.bashrc
+source /opt/ros/humble/setup.bash
+source /workspace/install/setup.bash
+export NAV2_MAP_PATH=/workspace/src/turtlebot3_simulations/turtlebot3_gazebo/map/office_map.yaml
 ```
 
 ## 2. 启动仿真