ROS 2 version

[gavanderhoorn]

We currently don't have plans for a port to ROS 2.

While it would not be too difficult, there are many other aspects which could currently benefit from our attention, and we'd like to address those first.

Additionally: there is nothing like rospypi/simple, which makes installing ROS 2 on Windows far more complex than what we currently use (simple venv with a requirements.txt file).