GitLab

* Rename index.mdx to index.md

* With saved modifs

* Address review comment

* Treat all files

* .mdx -> .md

* Remove special char

* Update utils/tests_fetcher.py
Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

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Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

* Update doc example feature extractor -> image processor

* Apply suggestions from code review

* 📝 update philosophy to include other preprocessing classes

* 🖍 apply feedbacks

* Reorganize doc for multilingual support

* Fix style

* Style

* Toc trees

* Adapt templates

* Convert all tutorials and guides

* Convert all remaining rst to mdx

* Track and fix bad links