Update the Tutorials/Getting Started Guides

Currently, Minterpy documentation only includes two tutorials (written in Jupyter notebooks): one-dimensional function interpolation and polynomial regression. The latter still uses the old interface of polynomial regression. In any case, these two tutorials are limited and must be extended to expose potential new users to Minterpy capabilities and help new users to get started with Minterpy.

I would propose to update the getting started part of the docs to include the following:

• One-Dimensional Polynomial Interpolation
• Multi-Dimensional Polynomial Interpolation
• Arithmetic with Polynomials
• Calculus with Polynomials
• Polynomial Regression