Crate approx_pearson_skew

Pearson skew second coeffiecient, using mean and median assuming immutable byte slice

References:

• Wolfram Skewness
• Wikipedia Standard Deviation (Population)

Usable on no_std due to use of approximate square root from micromath

Functions

kth_ind	Find kth value index from unsorted immutable slice
mean	Mean/Average value of byte in slice
median	Find median from unsorted immutable slice
next_min	Determine the next minimum index and count of occurances
pearson_skew_median	Pearson second skew coefficient, based on the difference between the average and median
std_dev_pop	Immutable slice population standard deviation