Fix documentation for ordering in @before_compile
Fix documentation for ordering in @before_compile

Closes #9334.
joshprice/elixir,ggcampinho/elixir,kelvinst/elixir,kimshrier/elixir,kimshrier/elixir,ggcampinho/elixir,pedrosnk/elixir,kelvinst/elixir,elixir-lang/elixir,pedrosnk/elixir,michalmuskala/elixir