Improve RenderDiagnosticsOverlayPlugin dependency docs

This section could be more clear about what dependencies are needed for the example code to work as displayed in the article
https://bevy.org/news/bevy-0-19/#diagnostics-overlay

also small typo here:
https://github.com/bevyengine/bevy/blob/244e0e6ae2c165a8d87b5e169768d5f70ab0f96d/crates/bevy_dev_tools/src/diagnostics_overlay.rs#L247C1-L247C73

`features = ["bevy_dev_tools"]` is required for the example code to be importable

```
...
FrameTimeDiagnosticsPlugin::default(),
MeshAllocatorDiagnosticPlugin,
MaterialAllocatorDiagnosticPlugin::::default(),
...
```
are required for
```
commands.spawn(DiagnosticsOverlay::fps());
commands.spawn(DiagnosticsOverlay::mesh_and_standard_material());
```
to not show "Missing" in the Overlay.

I think a solution could be a console printed warning saying something about needing X plugin for this metric to have access to the metric.

The 0.19 release section could mention this or link to somewhere mentioning the dependencies/setup required to get identical results as shown in the image in the article.

---

As an aside - I think a general pain point I've had with bevy built-in plugins (and my own) is that there is little documentation or visibility into what each plugin depends on for certain functionality. Maybe having some way to quickly check the docs for all plugins and features that are needed for a component/resource/asset/plugin to function with no limitations could help improve this.

Start with the linked Bevy 0.19 diagnostics overlay article and crates/bevy_dev_tools/src/diagnostics_overlay.rs around line 247. Check the example's feature and plugin dependencies, correct the noted typo, and clarify the setup needed to reproduce the article's overlay; done means the documentation explains why the metrics are available without showing "Missing".

Written by the indexing model from the issue text.