docs: Add example to README

README.md

@@ -10,6 +10,12 @@ I used multiple datasets for generalizing the model for both colloquial and writ
 
 The script which is used to pre-train model is [here](https://github.com/cosmoquester/transformers-bart-training).
 
+When you use the reference API, you must wrap the sentence with `[BOS]` and `[EOS]` like below example.
+
+```
+[BOS] 안녕하세요? 반가워요~~ [EOS]
+```
+
 ## Used Datasets
 
 ### [모두의 말뭉치](https://corpus.korean.go.kr/)