Remove docstrings from overriding methods

[lars-reimann]

Once Griffe supports the inheritance of docstrings (mkdocstrings/griffe#96), remove docstrings that simply repeat what's written in the parent class. This affects the fit and predict methods of all Classifiers and Regressors for example.

[zzril]

What was the issue that blocked this? #58?

[lars-reimann]

The linked issue in griffe. Unless we submit a PR there, we need to wait until this gets implemented by someone else.

[lars-reimann]

The downside would be that we could not add examples that are specific to the subclass.