docs: Make 'how to open a PR' title match filename
docs: Make 'how to open a PR' title match filename

- This is a bit of a cheat to get around the titlecase lint. But I
  wasn't sure whether to ignore it or not. And there've been previous
  comments about making filenames match titles, so...

EricFromCanada/brew,sjackman/homebrew,reitermarkus/brew,claui/brew,EricFromCanada/brew,nandub/brew,reitermarkus/brew,vitorgalvao/brew,MikeMcQuaid/brew,mahori/brew,konqui/brew,vitorgalvao/brew,claui/brew,nandub/brew,Homebrew/brew,konqui/brew,vitorgalvao/brew,sjackman/homebrew,claui/brew,reitermarkus/brew,claui/brew,sjackman/homebrew,EricFromCanada/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,konqui/brew,nandub/brew,Homebrew/brew,JCount/brew,JCount/brew,vitorgalvao/brew,MikeMcQuaid/brew,sjackman/homebrew,mahori/brew,Homebrew/brew,JCount/brew,mahori/brew,Homebrew/brew,reitermarkus/brew,EricFromCanada/brew,mahori/brew,JCount/brew,konqui/brew,nandub/brew