add library.json

library.json

+{
+"name": "Audio",
+"frameworks": "Arduino",
+"platforms": "Teensy",
+"keywords": "sound, audio, FFT, filter, effect",
+"description": "Teensy Audio Library",
+"url": "http://www.pjrc.com/teensy/td_libs_Audio.html",
+"downloadUrl": "http://www.pjrc.com/teensy/arduino_libraries/Audio.zip",
+"authors":
+{
+	"name": "Paul Stoffregen",
+	"maintainer": true
+}
+"repository":
+{
+    "name": "git",
+    "url": "https://github.com/PaulStoffregen/Audio"
+}
+}