fix README.md

README.md

@@ -98,7 +98,7 @@ for a joint word segmentation and sequence labeling (e.g, POS-tagging, NER) mode
 The format of the train/dev/test files is tsv.
 Each line is `word`  and `tag` and one line is represented by `word` \t(tab) `tag`.
 Note that you put EOS between sentences.
-Refer to [sample datasets](/nagisa/data/sample_datasets) and [Tutorial (Train a model for Universal Dependencies)](https://nagisa.readthedocs.io/en/master/tutorial.html).
+Refer to [sample datasets](/nagisa/data/sample_datasets) and [Tutorial (Train a model for Universal Dependencies)](https://nagisa.readthedocs.io/en/latest/tutorial.html).
 
 
 ```