Improve docs on map field access
Improve docs on map field access

kelvinst/elixir,kimshrier/elixir,kelvinst/elixir,michalmuskala/elixir,elixir-lang/elixir,pedrosnk/elixir,joshprice/elixir,ggcampinho/elixir,pedrosnk/elixir,kimshrier/elixir,ggcampinho/elixir