Update MJX documentation reference to MJWarp viewer

PiperOrigin-RevId: 881941624
Change-Id: Ieafb85f5b543a3d9212b33191579c1f7a7c09d16

doc/mjwarp/index.rst

@@ -216,6 +216,8 @@ Benchmark an environment with _`testspeed`
 
     mjwarp-testspeed benchmark/humanoid/humanoid.xml
 
+.. _mjwViewer:
+
 Interactive environment simulation with MJWarp
 
 .. code-block:: shell
@@ -489,7 +491,7 @@ Key features:
   `Warp's BVHs <https://nvidia.github.io/warp/api_reference/_generated/warp.Bvh.html#warp.Bvh>`__.
 
 Basic Usage
-----------
+-----------
 
 Rendering or raycasting requires a :class:`mjw.RenderContext <mujoco_warp.RenderContext>` which contains BVH structures,
 rendering specific fields, and output buffers.

doc/mjx.rst

@@ -119,7 +119,7 @@ Notice that we pass two extra arguments to ``mjx.make_data``:
 
 * ``naconmax`` defines the maximum number of contacts for all worlds combined.
 * ``njmax`` defines the maximum number of constraints per world. If you are developing a new scene, these parameters
-  should be tuned by loading them in the :ref:`viewer <MJW_Cli>` and increasing the values accordingly as overflows
+  should be tuned by loading them in the :ref:`viewer <mjwViewer>` and increasing the values accordingly as overflows
   occur. Scale ``naconmax`` by the number of environments you'll eventually need in a ``jax.vmap``!
 
 Contacts