message: Export the EncodableLayout trait
  This trait is used to bound the `save` method on ImageBuffer and
  DynamicImage which avoids leaking the implementation detail of using
  bytemuck for casting particular channel slices to bytes. This trait is
  sealed so there are little breakage risks, this allows downstream crates
  to name it as a bound.
diff: @@ -166,7 +166,7 @@ pub use crate::buffer_::{
  pub use crate::flat::FlatSamples;
  // Traits
  -pub use crate::traits::{Primitive, Pixel};
  +pub use crate::traits::{EncodableLayout, Primitive, Pixel};
  // Opening and loading images
  pub use crate::io::free_functions::{guess_format, load};
  