Update linux_i2c.py

Add note to clarify returned value from `__i2c_rdwr__` method

Author: santaimpersonator

qwiic_i2c/linux_i2c.py

@@ -302,4 +302,5 @@ def __i2c_rdwr__(self, address, write_message, read_nbytes):
 				pass
 
 		# Return read transaction (list)
-		return read
+		# Note - To retreive values, list the return: list(read)
+		return read