Updated readme of NER scenario.
+# Named Entity Recognition (NER)
+Named Entity Recognition (NER) is the task of detecting and classifying
+real-world objects mentioned in text. Common named entities include person
+names, locations, organizations, etc. The state-of-the art NER methods include
+combining Long Short-Term Memory neural network with Conditional Random Field
+(LSTM-CRF) and pretrained language models like BERT. NER can be used for
+information extraction and filtering. It also plays an important role in other
+NLP tasks like question answering and texts summarization.
