Add backend login credentials and 2FA setup instructions to README

[YevhenZvieriev]

This PR fixed #1204 and includes updates to both the README file and the setup script:

• README:

  • Added default login credentials: username john.smith and password password123.
  • Included instructions on how to configure or disable Two-Factor Authentication (2FA).
  • Added troubleshooting steps for common login issues.

• Setup Script:

  • Added an echo statement to display the URL and default credentials for accessing the Magento backend after installation.

These changes provide clear guidance for users to access the backend easily and configure their Magento instance effectively.

[what-the-diff]

PR Summary

• Improved README.md Documentation

  • Added instructions for accessing the Magento Backend, along with the necessary credentials for login.
  • Included detailed steps for setting up and disabling Two-Factor Authentication (2FA).
  • Updated the email info related to Mailcatcher for better clarity on port usage.

• Enhancements to the setup Script

  • The script now checks for the existence of the magento.env file and sources it, issuing a warning if it's not found.
  • The script will now also display the Magento backend URL and the default login credentials. This should make the process easier for new users.

[markshust]

@YevhenZvieriev so great! This will definitely help eliminate many headaches. I made a minor change with the verbiages around checking emails with 2FA, but all looks good and merged in 👍