update doxygen

Framework/Geometry/src/Instrument/Detector.cpp

@@ -92,8 +92,11 @@ double Detector::getSignedTwoTheta(const V3D &observer, const V3D &axis,
   return angle;
 }
 
-/// Get the phi angle between the detector with reference to the origin
-///@return The angle
+/** Get the phi angle between the detector with reference to the origin
+ * This function will not be supported in Instrument-2.0 due to its ambiguity.
+ * DO NOT USE IN NEW CODE
+ * @return The angle
+ */
 double Detector::getPhi() const {
   const Kernel::V3D pos = this->getPos();
   return std::atan2(pos[1], pos[0]);