String representation of logged instances should be configurable

[Ozzypig]

local part = workspace.Part
Logging:info("%s is my favorite part", part) --> not currently possible, see #5 
Logging:info("%s is my favorite part", part.Name)
Logging:info("%s is my favorite part", part:GetFullName())

Doing print(part) uses the part's name as if it were tostring(part). It would be nice to have a configuration that switches to the result of Instance:GetFullName. While it is not possible to use %s with an instance (see #5), it should be possible to use the full name for more verbose logging.

This begs the question of where such configurations should live, e.g. all loggers in general (like level), the root logger only, or on formatters.