Added set operation

v2.1

Updated steps to install

Added functions - Distinct, Remove, Max, Min, Some

Added functions - Distinct, Remove, Max, Min, Some . Renamed few functions.

Added functions - FilterMap and Every

v1.2

Fixed panic when nil is passed as any of the parameter in the function

With installation steps: Still Filter and Map

v1.1

updated readme

Map and Filter are in this release

v1.0

Updated readme