Support installation of major version number: vfox install deno@2

[tianyiw2013]

> vfox install deno@2.3
Preinstalling deno@2.3.7...

> vfox install deno@2
Preinstalling deno@2.3.7...

[Copilot]

Pull Request Overview

This PR adds support for installing Deno using major version numbers (e.g., vfox install deno@2) by implementing version prefix matching to automatically resolve to the latest available version within that major version.

• Refactored the PreInstall function to support partial version matching with major version numbers
• Added a new result helper function to reduce code duplication
• Updated the README to use the GitHub URL instead of the documentation URL

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
hooks/pre_install.lua	Implements major version matching logic and extracts common result building into a helper function
README.md	Updates vfox project URL to point to GitHub repository

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