Modify description of ``min_samples``

[chenxinye]

Setting min_samples to None, then min_samples should be equal to min_cluster_size .

This request is to modify the parameter descriptions of min_samples, to ensure the HDSBCAN's documentation is aligned with parameter descriptions in https://scikit-learn.org/stable/modules/generated/sklearn.cluster.HDBSCAN.html#sklearn.cluster.HDBSCAN.

Thanks

[lmcinnes]

Thanks!