Fix current warnings

[gbartolini]

Fix these warnings:

[INFO] Starting the development server...
[WARNING] The `siteConfig.onBrokenMarkdownLinks` config option is deprecated and will be removed in Docusaurus v4.
Please migrate and move this option to `siteConfig.markdown.hooks.onBrokenMarkdownLinks` instead.
[SUCCESS] Docusaurus website is running at: http://localhost:3000/

✔ Client
  Compiled successfully in 11.69s

[WARNING] Docusaurus found 1 unused Markdown directives in file "versioned_docs/version-1.25/cloudnative-pg.v1.md"
- :map (575:157)
Your content might render in an unexpected way. Visit https://github.com/facebook/docusaurus/pull/9394 to find out why and how to fix it.
[WARNING] Docusaurus found 1 unused Markdown directives in file "versioned_docs/version-1.27/cloudnative-pg.v1.md"
- :map (577:157)
Your content might render in an unexpected way. Visit https://github.com/facebook/docusaurus/pull/9394 to find out why and how to fix it.
[WARNING] Docusaurus found 1 unused Markdown directives in file "versioned_docs/version-1.28/cloudnative-pg.v1.md"
- :map (577:157)
Your content might render in an unexpected way. Visit https://github.com/facebook/docusaurus/pull/9394 to find out why and how to fix it.
[WARNING] Docusaurus found 1 unused Markdown directives in file "docs/cloudnative-pg.v1.md"
- :map (577:157)
Your content might render in an unexpected way. Visit https://github.com/facebook/docusaurus/pull/9394 to find out why and how to fix it.
client (webpack 5.102.1) compiled successfully
```