Restore dragons to their seat of power (#13124)

# Objective

- There is an unfortunate lack of dragons in the meshlet docs.
- Dragons are symbolic of majesty, power, storms, and meshlets.
- A dragon habitat such as our docs requires cultivation to ensure each
winged lizard reaches their fullest, fiery selves.

## Solution

- Fix the link to the dragon image.
- The link originally targeted the `meshlet` branch, but that was later
deleted after it was merged into `main`.

---

## Changelog

- Added a dragon back into the `MeshletPlugin` documentation.

crates/bevy_pbr/src/meshlet/mod.rs

@@ -107,7 +107,7 @@ const MESHLET_MESH_MATERIAL_SHADER_HANDLE: Handle<Shader> =
 ///
 /// This plugin does not work on the WebGL2 backend.
 ///
-/// ![A render of the Stanford dragon as a `MeshletMesh`](https://raw.githubusercontent.com/bevyengine/bevy/meshlet/crates/bevy_pbr/src/meshlet/meshlet_preview.png)
+/// ![A render of the Stanford dragon as a `MeshletMesh`](https://raw.githubusercontent.com/bevyengine/bevy/main/crates/bevy_pbr/src/meshlet/meshlet_preview.png)
 pub struct MeshletPlugin;
 
 impl Plugin for MeshletPlugin {