Update README

Signed-off-by: shiyu22 <shiyu.chen@zilliz.com>

README.md

@@ -48,9 +48,46 @@ collection.load()
 
 Create the operator via the following factory method:
 
-***ann_insert.milvus_client(collection)***
+***ann_insert.milvus_client(host, port, collection_name, user= None, password=None, collection_schema=None, index_params=None)***
+
+**Parameters:**
+
+***host:*** *str*
+
+The host for Milvus.
+
+***port:*** *str*
+
+The port for Milvus.
+
+***collection_name:*** *str*
+
+The collection name for Milvus.
+
+***user:*** *str*
+
+The user for Zilliz Cloud, defaults to None.
+
+***password:*** *str*
+
+The password for Zilliz Cloud, defaults to None.
+
+
 
 <br />
 
 
-**Returns:** *None*
+
+## Interface
+
+Insert Milvus data.
+
+**Parameters:**
+
+***data:*** *list*
+
+The data to insert into milvus.
+
+**Returns:** MutationResult
+
+A MutationResult object contains `insert_count` represents how many and a `primary_keys` of primary keys.