Hey,

I needed to Serialize AnimationCurve and Keyframe and though I was able to create formatters and added them to MessagePack (amazing abstraction by the way) it wasn't implemented very well and I'm sure other people would appreciate that.

I am aware that MessagePackSerializer can serialize Vector2, Vector3, Quaternion, Color, Bounds, Rect. However, there are a few types which you might want to consider including:

• AnimationCurve
• Keyframe
• Matrix4x4
• Gradient
• Colour32 (Might already be included but not advertised)
• RectOffset

And I believe LayerMask is already serialized as an int.

Thanks for the amazing work on this project 😄