DOC: enhance documentation

Modules/Applications/AppClassification/app/otbTrainRegression.cxx

@@ -164,6 +164,12 @@ void DoInit()
   Superclass::DoInit();
 
   AddRANDParameter();
+
+  // Doc example parameter settings
+  SetDocExampleParameterValue("io.il", "training_dataset.tif");
+  SetDocExampleParameterValue("io.out", "regression_model.txt");
+  SetDocExampleParameterValue("io.imstat", "training_statistics.xml");
+  SetDocExampleParameterValue("classifier", "svm");
 }
 
 void DoUpdateParameters()

Modules/Applications/AppClassification/include/otbLearningApplicationBase.h

@@ -72,6 +72,8 @@ namespace Wrapper
  *
  * \sa TrainImagesClassifier
  * \sa TrainRegression
+ *
+ * \ingroup OTBAppClassification
  */
 template <class TInputValue, class TOutputValue>
 class LearningApplicationBase: public Application