Add a generic error handling guide

[darach]

Experienced production tremor users who have grown up with tremor and how it
can manage, compensate, drop or process runtime errors have had the benefit
of face time with tremor maintainers.

We need to document the development and production practices as a guide as
it can be confusing for new adopters and users of tremor and the documentation
we have produced in this regard is weak to this date.

The guide should cover ( post a comment to add to this list, dear readers ):

• Configuring rust logging levels on the command line
• Configuring and redirecting errors via the error port and connectors
• Other common runtime error handling strategies

The guide should not cover QoS, FT, HA as this is a separate topic and requires
an application or system flow model and set of needs to be useful.