Power BI Visuals Documentation

Hello all,

I'm new in this topic (develop own visuals for Power BI) and investigated today the documents and tutorials found here and at github.
After installed and executed the Bar Chart example I would like to upgrade it with the "Data labels" property.

My Problem: I can not find any documentation how to implement this.

Is there something like MSDN where I can find the definitions of all properties, something like MSDN for C#?
Are there any additional documentations?

Many thanks & Best regards
Alex