Colors definition of the transition

[gosolivs]

Add the description of the colors on the graph of transitions.

[smolk0]

@gosolivs
Nice idea!
Description for curve colors will be very useful.

Frankly speaking current blue/green/black colors rather confusing for me (sure it is just my opinion)
For example:
curve easeInSine has green color on the end with high tangent slope (fast animation speed)
curve easeOutSine has green color also on the end but already with low tangent slope (low animation speed)

What do you think if to paint curve segments with low tangent slope?