Improve docs for binwrite, closes #8746
Improve docs for binwrite, closes #8746

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