Support specifying :default spec in custom indentation rules

[camsaul]

Sometimes the default fuzzy rule for ^with- of [[:inner 0]] is inappropriate, for example if you had a function like

(defn with-timezone [t zone]
  ...)
 
;;; this is a regular function and should follow `:default` list indentation rules
(with-timezone (java.time.OffsetDateTime/now)
               "US/Pacific")

This PR adds support for explicitly specifying :default formatting for a specific symbol

[weavejester]

Thanks for the PR. This seems like a useful addition. Can you change the commit message to:

Add ':default' custom indentation rule

This puts it under 50 characters.

[camsaul]

@weavejester done

[weavejester]

Merged. Thanks for the work (again!)