External PHP: Update to PR #29

[MeowSky49887]

External PHP Support

Description:

This update introduces the ability to add and remove external PHP versions to the PHP Version Manager (PVM). Users can now manage custom PHP installations by specifying the path to the PHP executable. This allows better flexibility for managing PHP versions that are not installed through PVM, but are available locally. (Reference: #23 on GitHub Discussions)

Features:

• pvm add : Adds a custom PHP version by specifying the path to an external PHP executable.
• pvm remove : Removes an externally added PHP version by specifying the path to the PHP executable.
• Supports managing non-PVM-installed PHP versions alongside those installed via PVM.
• Enhances compatibility with multiple PHP installations, including system-wide or custom versions.
• pvm install add new argument for specify installation path (pvm install [nts] [path]).
• Updated Documentation: The README.md has been updated with setup instructions and details about the new commands.

[hjbdev]

Once this is ready I'll review it alongside #29 and hopefully merge into the one release