Describe the issue linked to the documentation

Hi.
In https://scikit-learn.org/stable/auto_examples/model_selection/plot_roc.html , there's section on "Plot ROC curves for the multilabel problem". At the end, it plots roc curve as this image, https://scikit-learn.org/stable/_images/sphx_glr_plot_roc_002.png, containing table name = "...characterictics to multi-class" . So either name or the image title is not true, since multilabel is we have more than one label for each sample, and multi class refers to the scenarios for non-binary problems(which can be single label or multi label).

Suggest a potential alternative/fix

Iris dataset is multiclass problem. Section name should be changed to multiclass. However, code seems to be valid for multi label case, also. Section name could cover both.