ADD platformio library.json

This adds platformio compatibility, when this library is pulled as a gitsubmodule (e.g. in adafruit's nrf52 framework).

Author: CSC-Sendance

library.json

@@ -0,0 +1,6 @@
+{
+    "name": "Adafruit TinyUSB Library",
+    "build": {
+        "libArchive": false
+    }
+}