Update README.md

README.md

@@ -23,7 +23,7 @@ This metric is used for evaluating the quality of relation extraction output. By
 This metric can be used in relation extraction evaluation.
 
 ## How to Use
-This metric takes 3 inputs, prediction, references(ground truth) and mode.Predictions and references are a list of list of dictionary of entity's name and entity's type. And mode define the evaluation type:
+This metric takes 3 inputs, prediction, references(ground truth) and mode. Predictions and references are a list of list of dictionary of entity's name and entity's type. And mode define the evaluation type:
 ```python
 import evaluate
 metric_path = "Ikala-allen/relation_extraction"