Returns a suggested decimal precision for format types that round to significant digits
given the specified numeric step and max values.
Parameters
step: number
The step represents the minimum absolute difference between values that will be formatted.
(This assumes that the values to be formatted are also multiples of step.)
max: number
max represents the largest absolute value that will be formatted.
Returns a suggested decimal precision for format types that round to significant digits given the specified numeric step and max values.