Update Readme.md

Author: ClutchplateDude

Addons/Readme.md

@@ -8,5 +8,5 @@ This is where we will place any user-contributed add ons to the mount that are s
 A motorization of the azimuth and altitude of the mount to help automate polar alignment.
 
 ### Digital Level
-A gyro/accelerometer to replace the bubble level. 
+A gyro/accelerometer to replace the bubble level. There is an additional holder that can also hold the GPS module. Additionally there is another arm that holds the GPS antenna and the Altitude driver board.