Redesign min command

[vanstee]

Similar to max, min can currently only be used to find the minimum among a list of args. We should instead find the min in the input list and allow variable substitution.

USAGE

min [$variable]

EXAMPLES

seed '[{"a": 2}, {"a": 1}, {"a": 3}]' | min
> {"a": 1}

seed '[{"a": 2}, {"a": 1}, {"a": 3}]' | min $a
> 1

seed '[{"a": {"b": 2}}, {"a": {"b": 1}}, {"a": {"b": 3}}]' | min $a.b
> 1