feat(compare): add export and share functionality

[Payal29037]

Pull Request

Description

This PR adds export and sharing functionality to the Compare page, making repository comparisons easier to save and share.

Changes Made

• Added a Copy as Markdown button that generates a Markdown-formatted comparison table suitable for GitHub issues, README files, and documentation.
• Added a Share Link button that generates a shareable URL containing the selected repositories as query parameters.
• Added support for loading repository comparisons directly from the repos query parameter, allowing users to share and reopen the same comparison.
• Preserved the existing comparison workflow and UI without affecting current functionality.

Fixes #34

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Chore / code cleanup / dependency update

Verification & Checklist

Verification

• npm run build completed successfully.
• npm run dev launches the application successfully.
• Copy as Markdown functionality tested manually.
• Share Link functionality tested manually.
• Repository comparisons can be restored from the generated URL.

Lint

• npm run lint executed successfully.

Note: The lint output reports existing project-wide warnings (unused imports, hook dependency warnings, etc.), but no new errors were introduced by this PR.

Please also confirm:

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code where appropriate.
• I have made corresponding changes to the documentation.
• My changes generate no new errors.

[vercel]

@Payal29037 is attempting to deploy a commit to the aditthyass' projects Team on Vercel.

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[AditthyaSS]

@Payal29037 Please Resolve the conflicts . Thanks for the Contribution