Add `Animatable protocol Properties` in readme
Add `Animatable protocol Properties` in readme

IBAnimatable/IBAnimatable,alexiosdev/IBAnimatable,seanwoodward/IBAnimatable,seanwoodward/IBAnimatable,JakeLin/IBAnimatable,JakeLin/IBAnimatable,alexiosdev/IBAnimatable,IBAnimatable/IBAnimatable,IBAnimatable/IBAnimatable