[processing] If algorithm has no short help, show description in algo…

…rithm dialog instead

src/gui/processing/qgsprocessingalgorithmdialogbase.cpp

@@ -485,6 +485,10 @@ QString QgsProcessingAlgorithmDialogBase::formatHelp( QgsProcessingAlgorithm *al
     }
     return QStringLiteral( "<h2>%1</h2>%2" ).arg( algorithm->displayName(), help );
   }
+  else if ( !algorithm->shortDescription().isEmpty() )
+  {
+    return QStringLiteral( "<h2>%1</h2><p>%2</p>" ).arg( algorithm->displayName(), algorithm->shortDescription() );
+  }
   else
     return QString();
 }