Document that reverse x reverse != identity
Document that reverse x reverse != identity

Closes #4038

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