update RELEASE_NOTES

documentation/RELEASE_NOTES.md

@@ -9,15 +9,19 @@ Changes have been made for getDouble, putDouble, getDoubleArray, putDoubleArray,
 1) Previously each only had support for a top level field named value.
 Each now allows access to a single sub field that has the correct type.
 Thus pvRequest must select a single field. For example
+
     pva->channel("PVRdumbPowerSupply")->putDouble(1.0,"power.value" );
 
 2) PvaChannel now has a method for each of the above.
 For example instead of
+
     PvaClientChannelPtr channel = pva->channel("PVRdouble");
     PvaClientPutPtr clientPut = channel->put();
     PvaClientPutDataPtr putData = clientPut->getData();
     putData->putDouble(1.0); clientPut->put();
+
 now it can be
+
     pva->channel("PVRdouble")->putDouble(1.0 );
 
 3) getDoubleArray and putDoubleArray work with any numeric scalar array