Modify docstring for rank correlation metrics

ignite/metrics/regression/kendall_correlation.py

@@ -55,6 +55,9 @@ class KendallRankCorrelation(EpochMetric):
             form expected by the metric. This can be useful if, for example, you have a multi-output model and
             you want to compute the metric with respect to one of the outputs.
             By default, metrics require the output as ``(y_pred, y)`` or ``{'y_pred': y_pred, 'y': y}``.
+        check_compute_fn: if True, ``compute_fn`` is run on the first batch of data to ensure there are no
+            issues. If issues exist, user is warned that there might be an issue with the ``compute_fn``.
+            Default, True.
         device: specifies which device updates are accumulated on. Setting the
             metric's device to be the same as your ``update`` arguments ensures the ``update`` method is
             non-blocking. By default, CPU.

ignite/metrics/regression/spearman_correlation.py

@@ -46,6 +46,9 @@ class SpearmanRankCorrelation(EpochMetric):
             form expected by the metric. This can be useful if, for example, you have a multi-output model and
             you want to compute the metric with respect to one of the outputs.
             By default, metrics require the output as ``(y_pred, y)`` or ``{'y_pred': y_pred, 'y': y}``.
+        check_compute_fn: if True, ``compute_fn`` is run on the first batch of data to ensure there are no
+            issues. If issues exist, user is warned that there might be an issue with the ``compute_fn``.
+            Default, True.
         device: specifies which device updates are accumulated on. Setting the
             metric's device to be the same as your ``update`` arguments ensures the ``update`` method is
             non-blocking. By default, CPU.