Allow broadcast description to be user-customized

[sgbaird]

streamingLambda/chalicelib/ytb_api_utils.py

Lines 101 to 105 in 32e1ce8

	broadcast_description = (
	f"Live camera feed from {workflow_name} stationed in Toronto, ON "
	"at the Acceleration Consortium (AC).\n\n"
	"https://acceleration.utoronto.ca/"
	)

Perhaps within https://github.com/AccelerationConsortium/ac-training-lab/blob/main/src/ac_training_lab/picam/my_secrets_example.py