Add .quantile(foo=quantiles) API?

[max-sixty]

Is your feature request related to a problem?

Many of our methods allow the equivalent of .shift(foo=5), where foo is a dimension name.

But not .quantile! That requires .quantile(dim="foo", [0,0.5,1])

Describe the solution you'd like

I guess this is a missing thing rather than a deliberate choice, is that right?

Describe alternatives you've considered

No response

Additional context

No response

[shoyer]

I think the API for quantile was adapted from aggregations like mean(), which only need a dimension name.

I agree that this would make sense here!