Added some comments on additional data packets that are parsed (RELPO…

…SNED and SVIN)

README.md

@@ -63,10 +63,16 @@ This library parses data from the following messages:
    * UBX-NAV-VELECEF
    * UBX-NAV-TIMEGPS
 
-Additionally, if high accuracy position data is available, it is also used.
+If high accuracy position data is available, it is also used.
    * UBX-NAV-HPPOSECEF
    * UBX-NAV-HPPOSLLH
 
+If relative position data is available, it is also used.
+   * UBX-NAV-RELPOSNED
+
+Finally, if survey in data is available, it is also used.
+   * UBX-NAV-SVIN
+
 Methods are provided in this library for automatically configuring the receiver to output the correct packets at the expected rate. Alternatively, the receiver can be configured in U-Center and this library used to parse the data for the microcontroller.
 
 # Ubx