Migrate model card from transformers-repo

Read announcement at https://discuss.huggingface.co/t/announcement-all-model-cards-will-be-migrated-to-hf-co-model-repos/2755
Original file history: https://github.com/huggingface/transformers/commits/master/model_cards/allegro/herbert-base-cased/README.md

README.md

@@ -0,0 +1,51 @@
+---
+language: pl
+tags:
+- herbert
+license: cc-by-sa-4.0
+---
+
+# HerBERT 
+**[HerBERT](https://en.wikipedia.org/wiki/Zbigniew_Herbert)** is a BERT-based Language Model trained on Polish Corpora
+using MLM and SSO objectives with dynamic masking of whole words.
+Model training and experiments were conducted with [transformers](https://github.com/huggingface/transformers) in version 2.9.
+
+## Tokenizer
+The training dataset was tokenized into subwords using ``CharBPETokenizer`` a character level byte-pair encoding with
+a vocabulary size of 50k tokens. The tokenizer itself was trained with a [tokenizers](https://github.com/huggingface/tokenizers) library. 
+We kindly encourage you to use the **Fast** version of tokenizer, namely ``HerbertTokenizerFast``.
+
+## HerBERT usage
+
+
+Example code:
+```python
+from transformers import AutoTokenizer, AutoModel
+
+tokenizer = AutoTokenizer.from_pretrained("allegro/herbert-base-cased")
+model = AutoModel.from_pretrained("allegro/herbert-base-cased")
+
+output = model(
+    **tokenizer.batch_encode_plus(
+        [
+            (
+                "A potem szedł środkiem drogi w kurzawie, bo zamiatał nogami, ślepy dziad prowadzony przez tłustego kundla na sznurku.",
+                "A potem leciał od lasu chłopak z butelką, ale ten ujrzawszy księdza przy drodze okrążył go z dala i biegł na przełaj pól do karczmy."
+            )
+        ],
+    padding='longest',
+    add_special_tokens=True,
+    return_tensors='pt'
+    )
+)
+```
+
+
+## License
+CC BY-SA 4.0
+
+
+## Authors
+Model was trained by **Allegro Machine Learning Research** team.
+
+You can contact us at: <a href="mailto:klejbenchmark@allegro.pl">klejbenchmark@allegro.pl</a>