💡 add rule utils docstring

docs/api/utils.md

@@ -25,7 +25,7 @@ sidebarDepth: 0
 * **返回**
 
     
-    * Callable[..., Awaitable[Any]]
+    * `Callable[..., Awaitable[Any]]`
 
 
 
@@ -34,35 +34,6 @@ sidebarDepth: 0
 基类：`json.encoder.JSONEncoder`
 
 
-* **类型**
-
-    `json.JSONEncoder`
-
-
-
 * **说明**
 
-    `JSONEncoder` used when encoding `Message` (List of dataclasses)
-
-
-
-### `default(o)`
-
-Implement this method in a subclass such that it returns
-a serializable object for `o`, or calls the base implementation
-(to raise a `TypeError`).
-
-For example, to support arbitrary iterators, you could
-implement default like this:
-
-```default
-def default(self, o):
-    try:
-        iterable = iter(o)
-    except TypeError:
-        pass
-    else:
-        return list(iterable)
-    # Let the base class default method raise the TypeError
-    return JSONEncoder.default(self, o)
-```
+    在JSON序列化 `Message` (List[Dataclass]) 时使用的 `JSONEncoder`