Updated README file.

README.md

@@ -24,5 +24,5 @@ To help get you get started on your software development, here are examples of n
 
 1. [Teleoperate Stretch with a Node](example_1.md) - Use a python script that sends velocity commands.  
 2. [Filter Laser Scans](example_2.md) - Publish new scan ranges that are directly in front of Stretch.
-2. Mobile Base Collision Avoidance - Stop Stretch from running into a wall.
-3. [Give Stretch a Balloon](example_3.md) - Create a "balloon" marker that goes where ever it goes.
+3. Mobile Base Collision Avoidance - Stop Stretch from running into a wall.
+4. [Give Stretch a Balloon](example_3.md) - Create a "balloon" marker that goes where ever it goes.