Add vale linting as a CI step
Add vale linting as a CI step

- So that people know when the docs they've written violate our style
  guides.

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