Update README.md to reflect the latest changes

The README.md file needs to also be updated to follow these guidelines: https://www.drupal.org/docs/develop/managing-a-drupalorg-theme-module-or... →

I updated the README.md file with some recent information to install / configure the theme, there were some misspellings that were fixed: https://git.drupalcode.org/project/sshop/-/pipelines/500453

I leave to "Needs Review" for a while just in case anyone wants extra points for testing !

I'll move it to "Fixed", any issues please let me know

Automatically closed - issue fixed for 2 weeks with no activity.