Installer for PVM: Update to 1.2.0

[MeowSky49887]

Add Installer for PVM

Description:

This update introduces an Inno Setup-based installer for PVM (PHP Version Manager). It simplifies the installation process, adds system PATH integration, and enhances uninstallation features.

Features:

• Automatic System PATH Update: The installer automatically adds PVM to the system PATH, making it accessible from the command line.
• Configurable Installation Location: Users can choose the directory where PVM should be installed.
• Uninstaller: A built-in uninstaller allows users to easily remove PVM and all associated files.
• Clean PATH Removal: When uninstalled, the installer includes a command to remove PVM from the system PATH.
• Uninstall Specific PHP Versions: Users can now uninstall specific PHP versions they no longer need.
• Newest Version Inclusion: Ensures that the most up-to-date PHP version is included in the version list. (Reference: #24 on GitHub Discussions)
• Updated Documentation: The README.md has been updated with setup instructions and details about the new commands.

PS:

Apologies for not providing a full description in the previous PR due to time constraints. I believe this update should be considered for a new minor version as it introduces the installer feature.

[Lotti]

Thank you for this contribute!

I was about to implement the uninstall command too :D
And also thinking about how to automate the first setup of pvm!

Can't wait to have your changes merged :D