My first release to akima spline interpolation

The akima interpolation is a very pretty one as it tries to mimic the natural flow when drawing lines through points with the hand. This is a modified version that builds on its original philosophy.

I made this, because I didn't like the options available because of either bad interpolation due to ringing or missing extrapolation support.

This really takes a big weight off me, as this is something that I needed since I first began using rust half a year ago.

Anyway, I just wanted to share this, so if someone has either never seen akima interpolation or desperately needs a quick and easy to use library for pretty interpolation go check it out!

Feedback is welcome!