Update intro_to_nav.md

ros1/intro_to_nav.md

@@ -14,6 +14,20 @@ For more details on the arguments, see the [API docs](https://github.com/hello-r
 
 Visualize the simulated robot in Rviz:
 
+```
+roslaunch stretch_gazebo gazebo.launch rviz:=true
+```
+
+## Teleoperation
+
+Switch to 'navigation' [mode](https://github.com/hello-robot/stretch_ros/tree/noetic/stretch_core#mode-std_msgsstring):
+
+```
+rosservice call /switch_to_navigation_mode
+```
+
+Run base teleop:
+
 ```
 TODO
 ```