Fixing typos

Author: Rogan Carr

docs/samples/Microsoft.ML.Samples/Dynamic/PermutationFeatureImportance.cs

@@ -144,7 +144,7 @@ public static void PFI_BinaryClassification()
             // rerun the script with a different seed set in the MLContext(), like so:
             //  `var mlContext = new MLContext(seed: 12345);`
             Console.WriteLine("Feature\tModel Weight\tChange in AUC");
-            var auc = permutationMetrics.Select(x => x.Auc).ToArray(); // Fetch r-squared as an array
+            var auc = permutationMetrics.Select(x => x.Auc).ToArray(); // Fetch AUC as an array
             foreach (int i in sortedIndices)
             {
                 Console.WriteLine($"{featureNames[i]}\t{weights[i]:0.00}\t{auc[i]:G4}");