Fix description for joint dynamics options

Co-authored-by: Silvio Traversaro <[email protected]>

docs/guide/configuration.rst

@@ -25,24 +25,22 @@ Testing
 For testing configurations, environment variables beginning with ``JAXSIM_TEST_`` are used. The following variables are available:
 
 - ``JAXSIM_TEST_SEED``: Defines the seed for the random number generator.
-  _Default: ``0``._
+  *Default:* ``0``.
 
 - ``JAXSIM_TEST_AD_ORDER``: Specifies the gradient order for automatic differentiation tests.
-  _Default: ``1``._
+  *Default:* ``1``.
 
 - ``JAXSIM_TEST_FD_STEP_SIZE``: Sets the step size for finite difference tests.
-  _Default: the cube root of the machine epsilon._
+  *Default:* the cube root of the machine epsilon.
 
 
 Joint Dynamics
 ~~~~~~~~~~~~~~
 Joint dynamics are configured using environment variables starting with ``JAXSIM_JOINT_``. Available variables include:
 
-- ``JAXSIM_JOINT_POSITION_LIMIT_DAMPER``: Defines the damper value for joint position limits.
-  _Default: ``0``._
+- ``JAXSIM_JOINT_POSITION_LIMIT_DAMPER``: Overrides the damper value for joint position limits of the SDF model.
 
-- ``JAXSIM_JOINT_POSITION_LIMIT_SPRING``: Defines the spring value for joint position limits.
-  _Default: ``0``._
+- ``JAXSIM_JOINT_POSITION_LIMIT_SPRING``: Overrides the spring value for joint position limits of the SDF model.
 
 
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