Complex / real-world example behavior trees

[aserbremen]

Hi,
thanks for your contribution for ros python behavior trees. The package looks really cool. I want to use ros2_ros_bt_py in a more complex high-level planning scenario, where the behavior tree is in charge of allocating jobs to robots, then trigger services of various ROS2 nodes, send goal poses, trigger and monitor actions.

I was wondering, if you can publish a more complex real-world behavior tree implementation using ros2_ros_bt_py. At the moment, I am not sure how to design subtrees, bt_nodes, or regular python nodes and how their interaction should look like. I am asking myself: what tasks should be done from wihtin the Web-UI or from within the python code.