[RU] basics/mix: improvements (#1800)
[RU] basics/mix: improvements (#1800)

* [RU] basics/mix: improvements

* Update mix.md

* Update mix.md

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