Adding singleRecord and averageRecord to Result's schema

[ViniRoveri]

Hey! It's me again lol

I noticed that you added the singleRecord and averageRecord properties when creating the Result object to count the amount of records of a person, but I thought it was also very helpful to have this data on the api as well when getting a result!

So I just added these fields to the json serialization function, and to the api documentation already as well

Also, I didn't add anything about these changes to the tests, cause it's fair that you do so the way you feel the most confortable

Cheers!