Docstring error on schema `distance_metrics` -> `distance_metric`

[bsbodden]

See https://github.com/RedisVentures/redisvl/blob/8d388011c22fea168c9ed3f40c2543614d655304/redisvl/schema/schema.py#L117

        # From Dict
        schema = IndexSchema.from_dict({
            "index": {
                "name": "user-index",
                "prefix": "user",
                "storage_type": "json",
            },
            "fields": [
                {"name": "user", "type": "tag"},
                {"name": "credit_score", "type": "tag"},
                {
                    "name": "embedding",
                    "type": "vector",
                    "attrs": {
                        "algorithm": "flat",
                        "dims": 3,
                        **"distance_metrics": "cosine",**
                        "datatype": "float32"
                    }
                }
            ]
        })