Update README.md file

[Dmytro Danylyk]

Sample code below will not compile since start() method doesn't return ArcAnimator object.

ArcAnimator arcAnimator = ArcAnimator.createArcShift(clipView, endX, endY, DEGREE, SIDE)
                    .setDuration(500)
                    .start();
``

[Asilbek Isakov]

I didn't pay enough attention. I'm sorry. I will fix it.

[Asilbek Isakov]

README.md updated