[style] fix install command on readme file

[alissn]

Update document.

[what-the-diff]

Pull Request Update 🚀👨‍💻

Great news! Our team has made an important change to make things smoother and easier.

• Command Modification 🎮💻

  The command we use to install modules has been upgraded from php artisan modules:install to php artisan module:filament:install. This change is all about making things more specific and improving efficiency, so you get to have a better and streamlined experience. This is a part of our continuous strive to put you, our cherished user, at the front and center, making sure your user experience is always top-class. 😊👍

Isn't that fantastic? Every day, we work a little harder to make things better for you! 🎉🚀