Created model card for xlm-roberta-xl (#38597)
* Created model card for xlm-roberta-xl
* Update XLM-RoBERTa-XL model card with improved descriptions and usage examples
* Minor option labeling fix
* Added MaskedLM version of XLM RoBERTa XL to model card
* Added quantization example for XLM RoBERTa XL model card
* minor fixes to xlm roberta xl model card
* Minor fixes to mask format in xlm roberta xl model card
