[IMP] README.md: Enhance documentation for profiles and optional serv…

[mrzingo]

This pull request makes several improvements and clarifications to the README.md documentation, focusing on how optional services are managed through Compose profiles, updating environment setup instructions, and enhancing clarity throughout the guide. The most important changes are grouped below:

Profiles and Optional Services:

• Added a new section, "Profiles and Optional Services", explaining how to enable optional containers (like pgadmin, keydb, minio, and acme) using the SERVICES and USE_* variables in the .env file, with configuration examples.
• Updated the PgAdmin instructions to reflect the new Compose profile-based approach, replacing the previous override file method. Now users enable PgAdmin by setting variables in .env and updating the SERVICES list.

Environment Setup and Actions:

• Clarified the process for bringing up and restarting environments, improved the explanation of the .env file, and updated environment-specific instructions for fresh, local, debug, testing, staging, and production setups. [1] [2]
• Removed the "Full" environment, clarified the staging and production environment steps, and updated section numbering and references throughout the documentation. [1] [2] [3]

General Documentation Improvements:

• Improved language and clarity in multiple sections, including tips for safe database management, search instructions, and alias definitions. [1] [2]
• Fixed minor typos, improved section organization, and updated links and references for consistency. [1] [2]

These changes make the documentation more accurate, easier to follow, and better aligned with the current project setup.