Docs: Add examples for the `onBeforeCompile` method in Material (#30043)

* Docs: Add examples for the onBeforeCompile method in Material

* Update Material.html

* Update Material.html

* Update Material.html

* Update Material.html

---------

Co-authored-by: Michael Herzog <michael.herzog@human-interactive.org>

docs/api/ar/materials/Material.html

@@ -404,6 +404,10 @@
 		<p>
 			This callback is only supported in `WebGLRenderer` (not `WebGPURenderer`). 
 		</p>
+		<p>
+			[example:webgl_materials_modified WebGL / materials / modified]<br />
+			[example:webgl_shadow_contact WebGL / shadow / contact]
+		</p>
 
 		<h3>
 			[method:undefined onBeforeRender]( [param:WebGLRenderer renderer], [param:Scene scene], [param:Camera camera], [param:BufferGeometry geometry], [param:Object3D object], [param:Group group] )

docs/api/en/materials/Material.html

@@ -426,6 +426,10 @@
 		<p>
 			This callback is only supported in `WebGLRenderer` (not `WebGPURenderer`). 
 		</p>
+		<p>
+			[example:webgl_materials_modified WebGL / materials / modified]<br />
+			[example:webgl_shadow_contact WebGL / shadow / contact]
+		</p>
 
 		<h3>
 			[method:undefined onBeforeRender]( [param:WebGLRenderer renderer], [param:Scene scene], [param:Camera camera], [param:BufferGeometry geometry], [param:Object3D object], [param:Group group] )

docs/api/fr/materials/Material.html

@@ -358,6 +358,10 @@
 		<p>
 			This callback is only supported in `WebGLRenderer` (not `WebGPURenderer`).
 		</p>
+		<p>
+			[example:webgl_materials_modified WebGL / materials / modified]<br />
+			[example:webgl_shadow_contact WebGL / shadow / contact]
+		</p>
 
 		<h3>
 			[method:undefined onBeforeRender]( [param:WebGLRenderer renderer], [param:Scene scene], [param:Camera camera], [param:BufferGeometry geometry], [param:Object3D object], [param:Group group] )

docs/api/it/materials/Material.html

@@ -376,6 +376,10 @@
 		<p>
 			This callback is only supported in `WebGLRenderer` (not `WebGPURenderer`). 
 		</p>
+		<p>
+			[example:webgl_materials_modified WebGL / materials / modified]<br />
+			[example:webgl_shadow_contact WebGL / shadow / contact]
+		</p>
 
 		<h3>
 			[method:undefined onBeforeRender]( [param:WebGLRenderer renderer], [param:Scene scene], [param:Camera camera], [param:BufferGeometry geometry], [param:Object3D object], [param:Group group] )

docs/api/zh/materials/Material.html

@@ -315,6 +315,10 @@
 <p>
 	This callback is only supported in `WebGLRenderer` (not `WebGPURenderer`). 
 </p>
+<p>
+  [example:webgl_materials_modified WebGL / materials / modified]<br />
+  [example:webgl_shadow_contact WebGL / shadow / contact]
+</p>
 
 <h3>
 	[method:undefined onBeforeRender]( [param:WebGLRenderer renderer], [param:Scene scene], [param:Camera camera], [param:BufferGeometry geometry], [param:Object3D object], [param:Group group] )