Add README.md file

The README.md was in the project but in a different location, it is now located in the root of the project correctly.

The README was in a different location, this location has been modified, however, the file requires a more detailed review of its structure and content.

I reviewed the structure of the README.md file and completed the missing sections, translating the remaining content into English and adjusting the formatting to follow the official Drupal README template.

I also created a merge request with these changes for your review.