rename example change_detection to have unique name (bevyengine#2419)

# Objective

Noticed a warning when running tests:
```
> cargo test --workspace
warning: output filename collision.
The example target `change_detection` in package `bevy_ecs v0.5.0 (/bevy/crates/bevy_ecs)` has the same output filename as the example target `change_detection` in package `bevy v0.5.0 (/bevy)`.
Colliding filename is: /bevy/target/debug/examples/change_detection
The targets should have unique names.
Consider changing their names to be unique or compiling them separately.
This may become a hard error in the future; see <rust-lang/cargo#6313>.
warning: output filename collision.
The example target `change_detection` in package `bevy_ecs v0.5.0 (/bevy/crates/bevy_ecs)` has the same output filename as the example target `change_detection` in package `bevy v0.5.0 (/bevy)`.
Colliding filename is: /bevy/target/debug/examples/change_detection.dSYM
The targets should have unique names.
Consider changing their names to be unique or compiling them separately.
This may become a hard error in the future; see <rust-lang/cargo#6313>.
```


## Solution

I renamed example `change_detection` to `component_change_detection`

Cargo.toml

@@ -259,8 +259,8 @@ name = "ecs_guide"
 path = "examples/ecs/ecs_guide.rs"
 
 [[example]]
-name = "change_detection"
-path = "examples/ecs/change_detection.rs"
+name = "component_change_detection"
+path = "examples/ecs/component_change_detection.rs"
 
 [[example]]
 name = "event"

examples/README.md

@@ -156,7 +156,7 @@ Example | File | Description
 Example | File | Description
 --- | --- | ---
 `ecs_guide` | [`ecs/ecs_guide.rs`](./ecs/ecs_guide.rs) | Full guide to Bevy's ECS
-`change_detection` | [`ecs/change_detection.rs`](./ecs/change_detection.rs) | Change detection on components
+`component_change_detection` | [`ecs/component_change_detection.rs`](./ecs/component_change_detection.rs) | Change detection on components
 `event` | [`ecs/event.rs`](./ecs/event.rs) | Illustrates event creation, activation, and reception
 `fixed_timestep` | [`ecs/fixed_timestep.rs`](./ecs/fixed_timestep.rs) | Shows how to create systems that run every fixed timestep, rather than every tick
 `hierarchy` | [`ecs/hierarchy.rs`](./ecs/hierarchy.rs) | Creates a hierarchy of parents and children entities