Extending BddDsl for Typed API

I created a parallel trait TBddDsl that allow to write tests for code using the Typed API.

An example of the code you can write is:

```scala
case class UserInfo(name: String, gender: String, age: Int)
case class EstimatedContribution(name: String, suggestedPensionContributionPerMonth: Double)

class TypedApiTest extends Specification with TBddDsl {

  "A test with a single source" should {

    "accept an operation from working with a single tuple-typed pipe" in {
      Given {
        List(("Joe", "M", 40), ("Sarah", "F", 22))
      } When {
        in: TypedPipe[(String, String, Int)] =>
          in.map[(String, Double)] { person =>
            person match {
              case (name, "M", age) => (name, (1000.0 / (72 - age)).toDouble)
              case (name, _, age) => (name, (1000.0 / (80 - age)).toDouble)
            }
          }
      } Then {
        buffer: mutable.Buffer[(String, Double)] =>
          buffer.toList mustEqual List(("Joe", 1000.0 / 32), ("Sarah", 1000.0 / 58))
      }
    }
    
    "accept an operation from single case class-typed pipe" in {
      Given {
        List(UserInfo("Joe", "M", 40), UserInfo("Sarah", "F", 22))
      } When {
        in: TypedPipe[UserInfo] =>
          in.map { person =>
            person match {
              case UserInfo(name, "M", age) => EstimatedContribution(name, (1000.0 / (72 - age)))
              case UserInfo(name, _, age) => EstimatedContribution(name, (1000.0 / (80 - age)))
            }
          }
      } Then {
        buffer: mutable.Buffer[EstimatedContribution] =>
          buffer.toList mustEqual List(EstimatedContribution("Joe", 1000.0 / 32), EstimatedContribution("Sarah", 1000.0 / 58))
      }
    }
  }   
}
```

I added this sample of code to the .md documentation file in the package directory