DOC: update Supsample docstring to the new v1 API (#680)

Author: Valentin-Laurent

mapie/subsample.py

@@ -16,8 +16,8 @@
 class Subsample(BaseCrossValidator):
     """
     Generate a sampling method, that resamples the training set with
-    possible bootstraps. It can replace KFold or  LeaveOneOut as cv argument
-    in the MAPIE class.
+    possible bootstraps. It can be used as cv argument in
+    :class:`~mapie.regression.JackknifeAfterBootstrapRegressor`.
 
     Parameters
     ----------