bin/init script to initialize development environment with sample data and dev-related modules

[aimanecouissi]

This PR adds a new init script to simplify Magento local environment setup.

Includes

• Deploys sample data
• Disables Two-Factor Authentication (dev only)
• Sets long admin session lifetime
• Generates URN catalog

Purpose

Streamlines the initialization process for local development, reducing manual steps.

[what-the-diff]

PR Summary

• README Update
  The instructions manual (README.md) has been updated with a fresh command. This lets users initiate the development setting populated with sample data and modules intended for development.

• New Automation Script
  We've introduced a new script, named 'bin/init'. This helps in automating the complete setup of the Magento development ecosystem. Processes like deploying the sample data, disabling two-factor authentication, and performing necessary setup instructions are automated, which saves time and reduces the possibility of human error.

• Makefile Help Upgrade
  A new instruction has been added to the Makefile help section to explain the functionality of the init command, providing users with understanding and guidance to utilize this new feature effectively.

[markshust]

This looks awesome -- will test it out momentarily

[markshust]

I optimized the script so setup:upgrade isn't executed twice. Also fixed the index:reindex command to indexer:reindex. Commit at fb9aa49

[markshust]

Updated README and etc. with this new script. Thanks, this is a big time-saver. Merging in, and I'll tag a new release shortly.