FIRST: the DotA2API project is from here: https://github.com/Auo/dota2-api. I didn't change anything about it and it's not my work at all.
The only thing I did is add the GetDotAData project which actually uses the PCL.
SECOND: You'll need to follow the instructions that project gives to get a steam key; just stick it in the app.config of the GetDotAData project and it should work just fine.
THIRD: ...Nah I just had the two things to say, nevermind.