fix(docs): resolve broken anchors and links in versioned docs

[VishalPainjane]

What has changed?

This PR fixes multiple broken internal links and anchors in the versioned documentation (v2 and v3) that were causing build failures.

Specifically, it addresses:

1. Updated incorrect relative paths (swapping ../../ to ../) in quickstart guides, platform requirements, and installation docs to correctly point to server/installation.md.
2. Added explicit anchors {#capturing-testcases} to server/installation.md in both v2.0.0 and v3.0.0 docs to ensure deep linking works reliably.
3. Fixed platform specific pages (mac-linux.md, windows-wsl.md) to point to the correct installation headers.

This PR Resolves #3649 issue in keploy repo

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 (if none of the other choices apply).

How Has This Been Tested?

I ran npm run build locally to verify that all broken link errors are resolved.

Build Output:

Checklist:

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.

[github-actions]

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