Fix documentation of ClassificationReport (#209)

* Fix values in example code

* Remove inconsistent empty lines

docs/machine-learning/metric/classification-report.md

@@ -36,7 +36,6 @@ After creating the report you can draw its individual metrics:
 
 ```
 $precision = $report->getPrecision();
-
 // $precision = ['cat' => 0.5, 'ant' => 0.0, 'bird' => 1.0];
 ```
 
@@ -63,6 +62,5 @@ $report->getSupport();
 // ['cat' => 1, 'ant' => 1, 'bird' => 3]
 
 $report->getAverage();
-// ['precision' => 0.75, 'recall' => 0.83, 'f1score' => 0.73]
-
+// ['precision' => 0.5, 'recall' => 0.56, 'f1score' => 0.49]
 ```