message: [pdsl_core] SyncedChunks::insert now returns old element
  This is required by StorageVec::replace.
  Also improved documentation.
diff: @@ -131,25 +131,22 @@ where
  None
  }
  - /// Inserts an entity into the n-th storage slot starting
  - /// from the key slot.
  + /// Inserts an entity into the n-th storage slot.
  ///
  /// # Note
  ///
  /// This will overwrite an already existing element.
  /// The inserted element is going to be synchonized from then on.
  - pub fn insert(&mut self, n: u32, val: T) {
  + pub fn insert(&mut self, n: u32, val: T) -> Option<T> {
  self.store_at(n, &val);
  - self.map_mut().insert(n, val);
  + self.map_mut().insert(n, val)
  }
  - /// Removes the entity stored at the n-th storage slot
  - /// starting from the key slot.
  + /// Removes the entity stored at the n-th storage slot.
  ///
  /// # Note
  ///
  - /// Returns the value that was previously stored in that slot
  - /// and otherwise `None`.
  + /// Returns the value that was previously stored in that slot if any.
  pub fn remove(&mut self, n: u32) -> Option<T> {
  if let Some(val) = self.load_at(n) {
  self.clear_at(n);
  