Add percentile function for p-quantile

[lulunac27a]

Description

Add percentile function for datasets with p-quantile based from an array of numbers. percentile value is 0 to 100.

Type of change

Please delete options that are not relevant.

• [x] New feature (non-breaking change which adds functionality)
• [x] This change requires a documentation update

How Has This Been Tested?

• [ ] If this is a new feature, did you add files to the examples directory to demonstrate the feature?
• [x] If this is a new feature, did you add documentation to the docs directory for the feature?