Update shaders.md

Appropriate TresShaderMaterial properties added to example code.

docs/cookbook/shaders.md

@@ -134,7 +134,7 @@ const blobRef = shallowRef(null)
       :position="[0, 4, 0]"
     >
       <TresSphereGeometry :args="[2, 32, 32]" />
-      <TresShaderMaterial />
+      <TresShaderMaterial :vertexShader="vertexShader" :fragmentShader="fragmentShader" :uniforms="uniforms"/>
     </TresMesh>
   </TresCanvas>
 </template>
@@ -171,4 +171,4 @@ And you could have a structure similar to this:
 │   ├── shaders/
 │       ├── vertexShader.glsl
 │       ├── fragmentShader.glsl
-```
+```