add encoder for orientation sub modules

src/encoders/index.ts

@@ -1,4 +1,6 @@
 import CentroidPosition from './motion/centroid-position';
+import OrientationEuler from './motion/orientation-euler';
+import OrientationQuaternion from './motion/orientation-quaternion';
 import RTTrPM from './motion/rttrpm';
 import Trackable from './motion/trackable';
 import RTTrPHeader from './rttrp-header';
@@ -8,4 +10,6 @@ export const Encoders = {
   RTTrPM,
   Trackable,
   CentroidPosition,
+  OrientationQuaternion,
+  OrientationEuler,
 };