fetch/h1-parsing/resources/README.md

`blue-with-0x00-in-a-header.asis` is a copy from `../../images/blue.png` with the following prepended using Control Pictures to signify actual newlines and 0x00:
```
HTTP/1.1 200 AN IMAGE␍␊
Content-Type: image/png␍␊
Custom: ␀␍␊␍␊
```