New Feature:
- support 'flow behavior' from JSON specification
- detect .json files via --customBehaviors
- log behavior progress while running
- logging tweaks (via browsertrix-behaviors 0.8.4) to limit logging for
custom behaviors
- differentiate logging for iframes, move more behavior messages to
debug
- move initCrawlState() to happen earlier to ensure Redis logging can happen in case of fatal errors
- docs to be added in separate follow-up PR
