Update README.md

Author: ShimmerEngineering

README.md

@@ -33,6 +33,9 @@ NOTE: The ShimmerClosedLibrary provides
 
 User's should note that IBI derived from ECG is more accurate than IBI derived from PPG.
 
+# Rev 0.9
+- Removed the double representation of the firmware version (FirmwareVersion) as there is no way to represent 0.1 ( where 0 is FirmwareMajor and 1 is FirmwareMinor) and 0.10 ( where 0 is FirmwareMajor and 10 is FirmwareMinor) as a double. FirmwareMajor and FirmwareMinor variables remain. Added two methods compareVersions which allows quick version comparisons
+
 # Rev 0.8
 - Updated ECG to HR and PPG to HR algorithms , now both support IBI
 - Updated 3D orientation example making it more user friendly