example sim_runner_callback_example.py needs the "rich" module

[viisatadi]

Given that the examples use this module, it should be an included requirement

Error message is:

python sim_runner_callback_example.py
Traceback (most recent call last):
  File "sim_runner_callback_example.py", line 3, in <module>
    from rich.logging import RichHandler
ModuleNotFoundError: No module named 'rich'

[nunobrum]

I'll probably remove this feature from the example on the next version. I prefer not to add yet another dependency. I'll close this issue when the next version is released.

[nunobrum]

The import rich has now a try: except ImportError: clause around it. If it is not found, then it is not used.