docs: update name of latest installer exe in download section

[libing0526]

📝 Change Type

Please select the type of change this PR introduces (choose one or more):

• feat: New feature.
• fix: Bug fix.
• docs: Documentation only changes.
• refactor: A code change that neither fixes a bug nor adds a feature.
• perf: Performance improvement.
• test: Adding missing tests or correcting existing tests.
• chore: Maintenance tasks (e.g., updating dependencies).

💡 Description

Updated the download section in README.md to display the installer filename as a clickable hyperlink instead of plain text URL, improving user experience and documentation readability.

Key Changes

1. Changed plain text URL to Markdown hyperlink format [Parallax_Win_Setup.exe](URL)
2. Display text shows the installer filename for better clarity
3. Clicking the link directly downloads the latest installer from GitHub releases

🔗 Related Issues

List any issues this PR closes or relates to:

• N/A

✅ Checklist

Please ensure the following points are addressed before merging:

• I have performed a self-review of my own code.
• I have added/updated tests that prove my fix or feature works (if applicable).
• I have updated the documentation (if necessary).
• My code follows the project's style guidelines.