Documentation improvement system_param.rs (#20157)

# Objective
Improvement of the documentation for SystemParam derive section so that
it mentions how to use a Query<&SomeComponent> as a SystemParam for a
struct that should have #[derive(SystemParam)].

## Solution
Added the documentation

---

## Showcase
the previous documentation
```rust
Query<'w, 's, Entity>,
Res<'w, SomeResource>,
ResMut<'w, SomeOtherResource>,
Local<'s, u8>,
Commands<'w, 's>,
EventReader<'w, 's, SomeEvent>,
EventWriter<'w, SomeEvent>
```
the new documentation
```rust
Query<'w, 's, Entity>,
Query<'w, 's, &'static SomeComponent>,  <================== the new thing
Res<'w, SomeResource>,
ResMut<'w, SomeOtherResource>,
Local<'s, u8>,
Commands<'w, 's>,
EventReader<'w, 's, SomeEvent>,
EventWriter<'w, SomeEvent>
```

crates/bevy_ecs/src/system/system_param.rs

@@ -55,6 +55,8 @@ use variadics_please::{all_tuples, all_tuples_enumerated};
 ///
 /// ```
 /// # use bevy_ecs::prelude::*;
+/// # #[derive(Component)]
+/// # struct SomeComponent;
 /// # #[derive(Resource)]
 /// # struct SomeResource;
 /// # #[derive(BufferedEvent)]
@@ -66,6 +68,8 @@ use variadics_please::{all_tuples, all_tuples_enumerated};
 /// # struct ParamsExample<'w, 's> {
 /// #    query:
 /// Query<'w, 's, Entity>,
+/// #    query2:
+/// Query<'w, 's, &'static SomeComponent>,
 /// #    res:
 /// Res<'w, SomeResource>,
 /// #    res_mut: