Fix typo in docs.

PiperOrigin-RevId: 565097458
Change-Id: I7a4440d72665d5db2853c18f72e83b130dde8d1a

doc/XMLreference.rst

@@ -1322,9 +1322,9 @@ also known as terrain map, is a 2D matrix of elevation data. The data can be spe
 
 .. _asset-hfield-content_type:
 
-:at:`content_type`: :at-val: `string, optional`
+:at:`content_type`: :at-val:`string, optional`
    If the file attribute is specified, then this sets the
-   `Media Type <https://www.iana.org/assignments/media-types/media-types.xhtml>`_ (formerly known as MIME types) of the
+   `Media Type <https://www.iana.org/assignments/media-types/media-types.xhtml>`__ (formerly known as MIME types) of the
    file to be loaded. Any filename extensions will be overloaded.  Currently ``image/png`` and
    ``image/vnd.mujoco.hfield`` are supported.
 

doc/changelog.rst

@@ -105,8 +105,8 @@ General
    :ref:`Cartesian actuator<actuator-general-refsite>` forces are realizable by individual motors at the joints.
    See :ref:`CForceRange` for details.
 #. Added an optional ``content_type`` attribute to hfield, texture, and mesh assets. This attribute supports a formatted
-   `Media Type <https://www.iana.org/assignments/media-types/media-types.xhtml>`_ (previously known as MIME type) string
-   used to determine the type of the asset file without resorting to pulling the type from the file extension.
+   `Media Type <https://www.iana.org/assignments/media-types/media-types.xhtml>`__ (previously known as MIME type)
+   string used to determine the type of the asset file without resorting to pulling the type from the file extension.
 #. Added analytic derivatives for quaternion :ref:`subtraction<mjd_subQuat>` and :ref:`integration<mjd_quatIntegrate>`
    (rotation with an angular velocity). Derivatives are in the 3D tangent space.
 #. Added :ref:`mjv_connector` which has identical functionality to :ref:`mjv_makeConnector`, but with more convenient