Add an Example for TrapezoidalRule Constructor (Func(Double, Double))

[Sahhary]

Please add an example for TrapezoidalRule Constructor (Func(Double, Double)).

TODO (optional): Describe a specific scenario you would like to see addressed.

Help Topic: http://accord-framework.net/docs/html/M_Accord_Math_Integration_TrapezoidalRule__ctor_1.htm