docs(speechRecognition): adds documentation for adaptive.speech

this commit adds API documentation to this project. there is still
some documentation missing, since a few API's aren't very clear
in my opinion. For example: .listen() and .payAttention() do not really
do something right?

you probably wanna review this commit. :)
Merge branch 'master' into docs
Merge pull request #18 from PascalPrecht/docs

docs(speechRecognition): adds documentation for adaptive.speech
Merge pull request #19 from angular-adaptive/canary

docs(speechRecognition): adds documentation for adaptive.speech