Major update to Getting Start section of the docs.

The Getting Started section of the Minterpy documentation has been extensively revised, now featuring a comprehensive Quickstart Guide and six detailed in-depth tutorials. These updates aim to provide users with a robust introduction to Minterpy, starting from the basics and gradually covering more advanced topics, enabling users to develop the necessary skills to effectively work with Minterpy.

This merge request addresses Issue #176 (closed) and is limited to documentation updates, with no changes made to the codebase.