Add French documentation to README

Problem

The README is not available in French, which makes it less accessible for French-speaking users.

This can limit understanding and reduce potential contributions from a significant part of the community.

Proposed solution

Add a French version of the README alongside the existing English and Spanish sections.

This could be done by:

• Translating the current content into French
• Structuring it similarly to other languages for consistency

I can contribute by providing the French translation.