Add Viewer.transform

docs/api/viewer.md

 
 The [pose](viewer-pose.md) of the viewer.
 
+### transform
+
+`viewer.transform: Transform, read-only`
+
+The [Transform](transform.md) of the viewer. The same as `pose.transform`.
+
+*Since:* 0.4.0
+
 ### view
 
 `viewer.view: View, read-only`

src/geometry/viewer.ts

     }
 
     /**
+     * The Transform of this viewer
+     * A shortcut to pose.transform
+     */
+    get transform(): Transform
+    {
+        return this._pose.transform;
+    }
+
+    /**
      * The view of this viewer (only for monoscopic rendering)
      */
     get view(): View