demos/hazard:

Added READMEs to the event-based, disagg, and complex fault (classical)
demos.
demos/hazard/LogicTreeCase2ClassicalPSHA/job.ini:

Corrected demo description.
demos/hazard/LogicTreeCase3ClassicalPSHA/job.ini:

Corrected demo description.
demos/hazard:

Added READMEs to the 3 logic tree classical demo cases.