fix a typo in bitwise documentation
fix a typo in bitwise documentation

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