Add instruction to use iex -S mix command (#1773)
Add instruction to use iex -S mix command (#1773)


doomspork/elixir_school,doomspork/elixir_school,nscyclone/elixir-school,nscyclone/elixir-school,nscyclone/elixir-school,doomspork/elixir-school,doomspork/elixir-school,doomspork/elixir_school,doomspork/elixir-school,nscyclone/elixir-school