Tutorial for creating scenarios using the execution manager

[alex-mitrevski]

For newcomers to the b-it-bots@Home, it would be useful to have a tutorial on how to create state machine-based scenarios using the execution manager.

The state machine definition language is described in [1] and is explained in the documentation of the component, but this does not address the composition of the already existing more primitive behaviours for defining complex behaviours. The tutorial should thus primarily focus on this aspect.

[1] A. Mitrevski and P. G. Plöger, "Reusable Specification of State Machines for Rapid Robot Functionality Prototyping," in Proceedings of the 23rd RoboCup International Symposium, Sydney, Australia, 2019.