* add post_process_semantic_segmentation method to BeiTFeatureExtractor
* Add tips * Add BEiT figure * Fix URL * Move tip to start * Add tip to TF model as well Co-authored-by: Niels Rogge <nielsrogge@Nielss-MacBook-Pro.local>
* Reorganize doc for multilingual support * Fix style * Style * Toc trees * Adapt templates