message: doc: Update the tunable exemple to include `MemoryUsage`.
diff: +use std::mem;
  use std::ptr::NonNull;
  use std::sync::Arc;
  +use loupe::{MemoryUsage, MemoryUsageTracker};
  use wasmer::{
  imports,
  vm::{self, MemoryError, MemoryStyle, TableStyle, VMMemoryDefinition, VMTableDefinition},
  @@ -131,6 +133,12 @@ impl<T: Tunables> Tunables for LimitingTunables<T> {
  }
  }
  +impl<T: Tunables> MemoryUsage for LimitingTunables<T> {
  + fn size_of_val(&self, _tracker: &mut dyn MemoryUsageTracker) -> usize {
  + mem::size_of_val(self)
  + }
  +}
  +
  fn main() -> Result<(), Box<dyn std::error::Error>> {
  // A Wasm module with one exported memory (min: 7 pages, max: unset)
  let wat = br#"(module (memory 7) (export "memory" (memory 0)))"#;
  