Add `markdown-link-check` with `pre-commit` to check for dead links in Markdown files

https://github.com/tcort/markdown-link-check

https://github.com/tcort/markdown-link-check?tab=readme-ov-file#run-as-a-pre-commit-hook

```
- repo: https://github.com/tcort/markdown-link-check
rev: ...
hooks:
- id: markdown-link-check
args: [-q]
```

We will need a config file with various rules:

https://github.com/tcort/markdown-link-check?tab=readme-ov-file#config-file-format

從 issue 中連結的 markdown-link-check README 區段開始，尤其是「Run as a pre-commit hook」和「Config file format」。確認 repository 的 pre-commit 設定位置，加入 hook 及其必要規則，然後對 Markdown 檔案執行已設定的 pre-commit 檢查，以確認死鏈會如預期般被回報。

由索引模型根據 Issue 內容生成。