message: add empty layer
diff: @@ -420,3 +420,8 @@ export function launch<R, E, A>(self: Layer<R, E, A>): T.Effect<R, E, never> {
  export function identity<R>() {
  return fromRawManaged(M.environment<R>())
  }
  +
  +/**
  + * Empty layer, useful for init cases
  + */
  +export const Empty = identity<unknown>()
  