message: update docs to be accurate to the change
diff: @@ -19,9 +19,6 @@ pub struct Storage<DB: HasJars> {
  /// Data shared across all databases. This contains the ingredients needed by each jar.
  /// See the ["jars and ingredients" chapter](https://salsa-rs.github.io/salsa/plumbing/jars_and_ingredients.html)
  /// for more detailed description.
  - ///
  - /// Even though this struct is stored in an `Arc`, we sometimes get mutable access to it
  - /// by using `Arc::get_mut`. This is only possible when all parallel snapshots have been dropped.
  shared: Shared<DB>,
  /// The "ingredients" structure stores the information about how to find each ingredient in the database.
  @@ -43,6 +40,9 @@ struct Shared<DB: HasJars> {
  /// Contains the data for each jar in the database.
  /// Each jar stores its own structs in there that ultimately contain ingredients
  /// (types that implement the [`Ingredient`] trait, like [`crate::function::FunctionIngredient`]).
  + ///
  + /// Even though these jars are stored in an `Arc`, we sometimes get mutable access to them
  + /// by using `Arc::get_mut`. This is only possible when all parallel snapshots have been dropped.
  jars: Option<Arc<DB::Jars>>,
  /// Conditional variable that is used to coordinate cancellation.
  