doc: improve doc Http2Stream: FrameError, Timeout and Trailers

doc/api/http2.md

@@ -970,6 +970,11 @@ an `Http2Stream`.
 added: v8.4.0
 -->
 
+* `type` {integer} The frame type.
+* `code` {integer} The error code.
+* `id` {integer} The stream id (or `0` if the frame isn't associated with a
+  stream).
+
 The `'frameError'` event is emitted when an error occurs while attempting to
 send a frame. When invoked, the handler function will receive an integer
 argument identifying the frame type, and an integer argument identifying the
@@ -984,14 +989,16 @@ added: v8.4.0
 The `'timeout'` event is emitted after no activity is received for this
 `Http2Stream` within the number of milliseconds set using
 `http2stream.setTimeout()`.
+Its listener does not expect any arguments.
 
 #### Event: 'trailers'
 <!-- YAML
 added: v8.4.0
 -->
 
 The `'trailers'` event is emitted when a block of headers associated with
-trailing header fields is received. The listener callback is passed the
+trailing header fields is received. Its listener does not expect any arguments.
+The listener callback is passed the
 [HTTP/2 Headers Object][] and flags associated with the headers.
 
 This event might not be emitted if `http2stream.end()` is called