Document how we pull bottles in Homebrew/linuxbrew-core
Document how we pull bottles in Homebrew/linuxbrew-core

- Also document some things that could go wrong and how to recover from
  them.

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