More Easing Functions For The Tween Machine

[CarbsCode]

Describe the new feature you would like to see and how it might function

It would be nice to have more easing functions such as:

Bounce
Elastic
EaseBack
etc.

More examples can be found here Easings

Which tool would this most likely be a new feature for?

Existing Tool: The Tween Machine

Additional context
There is a little difficulty when it comes to rounding when it comes to these functions. Aseprite and pixels work explicitly in integers where as some easing functions may only work with floating point numbers. This of course is handled a bit in the tool already with the custom interpolate functions which handle the progressive error but it can be a little tricky still to get this to work correctly.

[CarbsCode]

I would like to add this feature in to The Tween Machine v1.4.0 if I can implement in a timely manner along with easeInOut tweeks mentioned in Issue #21