Add a script to detect broken links in Markdown documentation

### Problem

The repository contains several Markdown documentation files such as:

- README.md
- docs/*.md
- examples documentation

Over time, some internal or external links in these files may become outdated or broken. This can negatively impact the user experience and make documentation less reliable.

Currently, broken links are typically detected manually during documentation reviews, which can be time-consuming and error-prone.

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### Proposed Solution

Introduce a script that scans Markdown files in the repository and detects broken links automatically.

The script could:

- recursively scan Markdown files (`*.md`)
- extract all links from the files
- validate both internal and external links
- report links that return invalid HTTP status codes (e.g., 404, 500)

### Benefits

- Improves documentation reliability
- Helps contributors detect outdated links early
- Reduces manual review effort
- Improves overall documentation quality