Show HN: Switch Git Users CLI

So I made this as a sugar for git config user.email whatever@gmail.com

What I have been doing by hand for some time is putting code for different customers in different directories and having a conditional in `~/.gitconfig` to determine what config applies there:

    [includeIf "gitdir:~/projects-private/**"]
      path = ./.gitconfig-private

    [includeIf "gitdir:~/projects-client/**"]
      path = ./.gitconfig-work

Switching to the right directory thus automatically changes the settings.

  #!/usr/bin/env zsh
  case $1 in
  foo)
      git config user.name 'John Doe'
      git config user.email john@example.com
      git config user.signingKey 0xFFFFFFFF
      ;;
  bar)
      git config user.name 'Jane Doe'
      git config user.email jane@example.com
      git config user.signingKey 0xEEEEEEEE
      ;;
  baz)
      git config user.name 'My Dog'
      git config user.email dog@example.com
      git config user.signingKey 0xDDDDDDDD
      ;;
  *)
      echo "usage: git-user foo|bar|baz" >&2
      exit 1
      ;;
  esac

Btw probably want to add signingKey support.