Update ros_workspace.md

Author: hello-binit

docs/ros_workspace.md

@@ -30,6 +30,10 @@ Your new ROS workspace is now set up successfully!
 
 This section provides suggestions for common errors that occur during installation. If you become stuck and don't find an answer here, please email us or contact us through [the forum](https://forum.hello-robot.com/).
 
+### UV not found failure
+
+If you see the errors regarding the `uv` CLI not being found in your log file (from `~/stretch_user/log/stretch_create_ament_workspace.<timestamp>_log.txt`), follow the [uv installation instructions](https://docs.astral.sh/uv/#getting-started) and then try updating the ROS workspace again.
+
 ### Rosdep failure on RTabMap
 
 After a failure, if you see the following error in your log file (from `~/stretch_user/log/stretch_create_ament_workspace.<timestamp>_log.txt`):