Rephrase comment about Local<T> for clarity. (Adopted) (#11129)

# Objective

- Finish PR #10322

## Solution

- Rebase changes in PR #10322 and format the changes.

Co-authored-by: Mauer-Oats <maueroats@users.noreply.github.com>

Author: tygyh

examples/ecs/ecs_guide.rs

@@ -224,8 +224,9 @@ fn exclusive_player_system(world: &mut World) {
 }
 
 // Sometimes systems need to be stateful. Bevy's ECS provides the `Local` system parameter
-// for this case. A `Local<T>` refers to a value owned by the system of type `T`, which is automatically
-// initialized using `T`'s `FromWorld`* implementation. In this system's `Local` (`counter`), `T` is `u32`.
+// for this case. A `Local<T>` refers to a value of type `T` that is owned by the system.
+// This value is automatically initialized using `T`'s `FromWorld`* implementation upon the system's initialization upon the system's initialization.
+// In this system's `Local` (`counter`), `T` is `u32`.
 // Therefore, on the first turn, `counter` has a value of 0.
 //
 // *: `FromWorld` is a trait which creates a value using the contents of the `World`.