You can't drag the part in to either schematic or pcb view (if you try it comes up with a circle with a diagonal bar to indicate an error.) You can drag the part in ...
If you would like to use the entire library, then download AdaFruit.fzbz, Adafruit_Feather.fzbz or Adafruit_Raspberry_Pi.fzbz and open it in Fritzing (File | Open ...