Add model cards for DeepPavlov models (#3138)

* add empty model cards for every current DeepPavlov model

* fix: replace cyrillic `с` with `c`

* docs: add model cards for current DeepPavlov BERT models

* docs: add links for arXiv preprints

model_cards/DeepPavlov/rubert-base-cased/README.md

@@ -0,0 +1,14 @@
+---
+language:
+- russian
+---
+
+# rubert-base-cased
+
+RuBERT \(Russian, cased, 12-layer, 768-hidden, 12-heads, 180M parameters\) was trained on the Russian part of Wikipedia
+and news data. We used this training data to build a vocabulary of Russian subtokens and took a multilingual version
+of BERT-base as an initialization for RuBERT\[1\].
+
+
+\[1\]: Kuratov, Y., Arkhipov, M. \(2019\). Adaptation of Deep Bidirectional Multilingual Transformers for Russian Language.
+arXiv preprint [arXiv:1905.07213](https://arxiv.org/abs/1905.07213).