Fix JSON.MERGE Summary (#2786)

* Fix JSON.MERGE Summary

* linters

Author: shacharPash

redis/commands/json/commands.py

@@ -261,7 +261,8 @@ def merge(
         decode_keys: Optional[bool] = False,
     ) -> Optional[str]:
         """
-        Sets or updates the JSON value at a path..
+        Merges a given JSON value into matching paths. Consequently, JSON values
+        at matching paths are updated, deleted, or expanded with new children
 
         ``decode_keys`` If set to True, the keys of ``obj`` will be decoded
         with utf-8.