Installation.md: add section for non-interactive installation
Installation.md: add section for non-interactive installation

Homebrew/brew,Homebrew/brew,JCount/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,nandub/brew,JCount/brew,Homebrew/brew,nandub/brew,nandub/brew,MikeMcQuaid/brew,Homebrew/brew,MikeMcQuaid/brew,JCount/brew,nandub/brew,JCount/brew