Support different thresholds for different entity types

It would be nice to be able to set a specific threshold for each entity type.

For example, we might want to match names perfectly, but allow a higher tolerance for other entity types.

The threshold could be either a float (current behavior) or a Path to a YAML or JSON configuration file:

threshold:
   name: 1.0
   age: 1.0
   location: 0.1
   occupation: 0.3