Create hook allowing polynomial regression

[lpatiny]

Would be nice to have the possibility to add a polynomial regression that display the function simply using a hook.

We would need to specify some props like:

• degree for polynomial regression
• show / hide function
• callback with fit information
• series id on which to attach the regression (and therefore the where to extract the data to send to polynomial regression).
• styling props to send to the function series returned by this hook

[targos]

I don't really want this package to start having large mljs dependencies.

[lpatiny]

Ok we could have this kind of example in the documentation then maybe.