Hello World example fails in Jupyter

[cmbant]

The trivial Hello World example uses an event loop via run_sync, which immediately gives error in Jupyter notebook because there's already an event loop - another example may be better, e.g. this works

result = await Runner.run(agent, "Write a haiku about recursion in programming.")

The problem is documented somewhere, but quite offputting for new user trying to get started:

openai-agents-python/src/agents/run.py

Line 286 in c8f3cdd

"""Run a workflow synchronously, starting at the given agent. Note that this just wraps the

[rm-openai]

Thanks, makes sense. We can update docs. cc @dmitry-openai in case you have time.

[dmitry-openai]

Adding #113