Update doc

lib/includes/nghttp2/nghttp2.h

@@ -1510,8 +1510,8 @@ typedef int (*nghttp2_on_stream_close_callback)(nghttp2_session *session,
  * different error code is desirable, use
  * `nghttp2_submit_rst_stream()` with a desired error code and then
  * return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`.  Again, use
- * `frame->push_promise.promised_stream_id` as stream_id parameter in
- * `nghttp2_submit_rst_stream()` if frame is PUSH_PROMISE.
+ * ``frame->push_promise.promised_stream_id`` as stream_id parameter
+ * in `nghttp2_submit_rst_stream()` if frame is PUSH_PROMISE.
  *
  * The implementation of this function must return 0 if it succeeds.
  * It can return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE` to
@@ -1574,12 +1574,15 @@ typedef int (*nghttp2_on_begin_headers_callback)(nghttp2_session *session,
  * included in the input bytes.
  *
  * Returning :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE` will close
- * the stream by issuing RST_STREAM with
- * :enum:`NGHTTP2_INTERNAL_ERROR`.  In this case,
+ * the stream (promised stream if frame is PUSH_PROMISE) by issuing
+ * RST_STREAM with :enum:`NGHTTP2_INTERNAL_ERROR`.  In this case,
+ * :type:`nghttp2_on_header_callback` and
  * :type:`nghttp2_on_frame_recv_callback` will not be invoked.  If a
  * different error code is desirable, use
  * `nghttp2_submit_rst_stream()` with a desired error code and then
- * return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`.
+ * return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`.  Again, use
+ * ``frame->push_promise.promised_stream_id`` as stream_id parameter
+ * in `nghttp2_submit_rst_stream()` if frame is PUSH_PROMISE.
  *
  * The implementation of this function must return 0 if it succeeds.
  * It may return :enum:`NGHTTP2_ERR_PAUSE` or