Enhance README with Detailed Setup Instructions and Development Environment Guide

[EmanueleEpi]

• Expanded the "Getting Started" section with detailed system prerequisites and step-by-step installation instructions for SuiteCRM.
• Added a new "Development Environment Setup" section to help contributors set up the project locally, including dependency installation and running the development server.
• Improved the "Contribute" section by providing clearer guidance on how to fork the repository, create a new branch, and submit a pull request (PR).
• Added troubleshooting tips to assist new users with potential installation issues.

[SuiteBot]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[shubham-pawar]

@EmanueleEpi Please sign the CLA.