Completed initial readme

README.md

@@ -20,13 +20,14 @@ using a dataset called [JFLEG](https://arxiv.org/abs/1702.04066).
 `pip install happytransformer `
 
 ```python
-from happytransformer import HappyTextToText
+from happytransformer import HappyTextToText, TTSettings
 
 happy_tt = HappyTextToText("T5", "vennify/t5-base-grammar-correction")
 
 args = TTSettings(num_beams=5, min_length=1)
 
-result = happy_tt.generate_text("This sentences has has bads grammar.", args=args)
+# Add the prefix "grammar: " before each input 
+result = happy_tt.generate_text("grammar: This sentences has has bads grammar.", args=args)
 
 print(result.text) # This sentence has bad grammar.