update link in particles tutorial (gazebosim#2127)

Signed-off-by: Ian Chen <[email protected]>

Author: iche033

tutorials/particle_tutorial.md

@@ -55,7 +55,7 @@ Here is the content of the Fog Generator [model.sdf](https://fuel.gazebosim.org/
   </model>
 ```
 
-The SDF 1.6+ specification supports having a `<particle_emitter>` SDF element as a child of `<link>`. The particle emitter itself has several properties that can be configured, see Gazebo Rendering's [particles tutorial](https://gazebosim.org/api/rendering/4.0/particles.html) for more details on these properties. In our Fog Generator model, we are using a box type particle emitter that covers a region size of 10 by 10m. By default, the particles are emitted in the `+x` direction, hence the model as a pitch rotation of -90 degrees to rotate the particle emitter so that the particles are emitted upwards in `+z`.
+The SDF 1.6+ specification supports having a `<particle_emitter>` SDF element as a child of `<link>`. The particle emitter itself has several properties that can be configured, see Gazebo Rendering's [particles tutorial](https://gazebosim.org/api/rendering/8/particles.html) for more details on these properties. In our Fog Generator model, we are using a box type particle emitter that covers a region size of 10 by 10m. By default, the particles are emitted in the `+x` direction, hence the model as a pitch rotation of -90 degrees to rotate the particle emitter so that the particles are emitted upwards in `+z`.
 
 Let's launch the example world to see what it looks like.