`separate-draft-pr-button` is in the wrong position

1. Try opening a PR, e.g. https://github.com/sindresorhus/refined-github/compare/unknow-feature-name?expand=1
2. See the buttons above the field rather than below

<img width="708" alt="Screen Shot" src="https://user-images.githubusercontent.com/1402241/103969734-35536200-512c-11eb-8b02-baaf86fdea32.png">
