This PR transfers the content from the README file to the docs folder, reorganizing the sections and improving the descriptions.

The main changes are:

• Move the sections "Installation", "Usage" and "Examples" to the docs/get-started/quickstart.md file.
• Improve the descriptions on the docs/index.rst file.
• Remove the duplicated content from the README, keeping only a brief description and links to the docs.

This will help to have a cleaner documentation, with installation and usage instructions on the docs, and the README acting as a summary.

Fixes #95.