Fix formatting of Groundedness score output

Author: anistark

src/ragas/prompt/metrics/response_groundedness.py

@@ -59,4 +59,4 @@ def response_groundedness_judge2_prompt(response: str, context: str) -> str:
 **Assertion:**
 [{response}]
 
-Do not explain.Based on the provided context and response, the Groundedness score is:"""
+Do not explain. Based on the provided context and response, the Groundedness score is:"""