add the most important contributor

CONTRIBUTORS.md

@@ -1,5 +1,9 @@
 # TinyUSB contributors (sorted alphabetically)
 
+* **[Adafruit Team](https://github.com/adafruit)**
+  * Main supporter and sponsor for hardware boards and kits
+  * Discussion and suggestion for feature and improvement
+
 * **[arturo182](https://github.com/arturo182)**
   * Board support for MiMX RT1010 evaluation kit