Amélioration configuration Docusaurus et implémentation i18n

- Add language switcher to navbar for bilingual site (FR/EN)
- Remove intro page, use presentation as entry point
- Add example pages to all documentation categories
- Configure categories with generated-index for page listings
- Update footer and homepage links to reference presentation
- Enhance configuration with best practices:
  - Add metadata and SEO keywords
  - Enable RSS/Atom feeds for blog
  - Configure sitemap generation
  - Add syntax highlighting for YAML, HCL, Docker
  - Enable Mermaid diagram support
  - Configure table of contents settings
  - Respect user color scheme preferences
  - Add last update metadata to docs
- Fix deprecated onBrokenMarkdownLinks configuration
- Create bilingual example pages with practical code examples
- Update all i18n translations for consistency

This update brings the site in line with Docusaurus 3.x best practices
and provides a solid foundation for documentation growth.

i18n/en/docusaurus-plugin-content-docs/current/notions/exemple.md

@@ -0,0 +1,34 @@
+---
+sidebar_position: 2
+---
+
+# Example
+
+This is an example page in the Concepts category.
+
+## Description
+
+This page demonstrates how to structure content in a category. It can contain:
+
+- Detailed explanations
+- Code examples
+- Diagrams
+- References
+
+## Usage
+
+You can duplicate this page to create new articles in this category.
+
+### Configuration
+
+To add a new page, create a `.md` file in the `docs/notions/` folder with the appropriate front matter:
+
+```yaml
+---
+sidebar_position: 3
+---
+```
+
+### Content
+
+Content can be written in Markdown or MDX to include custom React components.