minor doc formatting improvements
minor doc formatting improvements

kimshrier/elixir,antipax/elixir,gfvcastro/elixir,ggcampinho/elixir,kelvinst/elixir,lexmag/elixir,gfvcastro/elixir,elixir-lang/elixir,ggcampinho/elixir,antipax/elixir,kelvinst/elixir,semahawk/elixir,beedub/elixir,joshprice/elixir,pedrosnk/elixir,semahawk/elixir,beedub/elixir,lexmag/elixir,pedrosnk/elixir,kimshrier/elixir,michalmuskala/elixir