* work in progress: custom_models * Update custom_models.mdx * Update custom_models.mdx * Update _toctree.yml * Update _toctree.yml * Update custom_models.mdx * Update custom_models.mdx * Update _toctree.yml * Update _toctree.yml Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>