[model_cards] Tag AR model languages

model_cards/asafaya/bert-base-arabic/README.md

+---
+language: arabic
+---
+
 # Arabic BERT Model
 
 Pretrained BERT base language model for Arabic

model_cards/aubmindlab/bert-base-arabert/README.md

+---
+language: arabic
+---
+
 # AraBERT : Pre-training BERT for Arabic Language Understanding
 
 **AraBERT** is an Arabic pretrained lanaguage model based on [Google's BERT architechture](https://github.com/google-research/bert). AraBERT uses the same BERT-Base config.

model_cards/aubmindlab/bert-base-arabertv01/README.md

+---
+language: arabic
+---
+
 # AraBERT : Pre-training BERT for Arabic Language Understanding
 
 **AraBERT** is an Arabic pretrained lanaguage model based on [Google's BERT architechture](https://github.com/google-research/bert). AraBERT uses the same BERT-Base config.