Update README.md

README.md

@@ -27,14 +27,16 @@ Install with pip:
 - scikit-learn==0.21.2
 - scipy==1.3.0
 - seaborn==0.9.0
-- sklearn==0.0
 - spacy==2.1.4
 
 **NOTE**: _spacy_ must not be version 2.1.5!
 
-English language model for spacy:
+For spacy to work, you also need an English language model. The smallest one can be downloaded like this:
 
-    python -m spacy download en-core-web-sm
+    python -m spacy download en_core_web_sm
+    
+For a list of all available models for English, please refer to the official [documentation](https://spacy.io/models/en).
+In general, the larger the model is, the better spacy's performance becomes.
 
 ## How to create knowledge graphs