Add `push_ros_namespace` alias to `push-ros-namespace`

[clalancette]

Bug report

push-ros-namespace is the current decorator used for pushing a ROS namespace within a Launch GroupAction. However, we think it is more aesthetically nice to use push_ros_namespace, so we should add that decorator as well. See https://github.com/ros2/ros2_documentation/pull/539/files#r388486312 for more details.

[HappySamuel]

Hi

I think there's a need to edit this guidance, else everyone will still using push_ros_namespace and stumbled until they found this push-ros-namespace solution

Best,
Samuel

[clalancette]

I think there's a need to edit this guidance, else everyone will still using push_ros_namespace and stumbled until they found this push-ros-namespace solution

Sorry, it's not clear to me what the issue is. We prefer push_ros_namespace in Rolling, and that is what is shown in the example you are talking about. For Foxy and Galactic, we only have push-ros-namespace, and the tutorials reflect that.

Either way, if you have a question about the usage please open a question on https://answers.ros.org. If you think you've genuinely found a bug, please either open a new issue on https://github.com/ros2/ros2_documentation (to update the documentation) or https://github.com/ros2/launch_ros.

[HappySamuel]

Thanks for the clarification, i didn't notice that is for Rolling. Sorry for causing trouble.