readme: update the example output
@@ -10,11 +10,11 @@ The log line format is: `ConnID ReqID HeaderName HeaderValue`, except the first
```
$ sudo h2olog -p $(pgrep -o h2o)
-888 1: HTTP/2.0
-888 1: :authority torumk.com
-888 1: :method GET
-888 1: :path /
-888 1: :scheme https
+888 1 RxProtocol HTTP/2.0
+888 1 RxHeader :authority torumk.com
+888 1 RxHeader :method GET
+888 1 RxHeader :path /
+888 1 RxHeader :scheme https
... and more ...
```
