Add sleep related data structures

PiperOrigin-RevId: 829055431
Change-Id: I1ccbd77a57044a754ae7db611b4c2c0010fbda53

doc/XMLreference.rst

@@ -460,6 +460,11 @@ adjust it properly through the XML.
 :at:`ccd_tolerance`: :at-val:`real, "1e-6"`
    Tolerance threshold used for early termination of the convex collision algorithm.
 
+.. _option-sleep_tolerance:
+
+:at:`sleep_tolerance`: :at-val:`real, "1e-4"`
+   Velocity tolerance below which sleeping is possible. Feature under development, documentation pending.
+
 .. _option-sdf_iterations:
 
 :at:`sdf_iterations`: :at-val:`int, "10"`
@@ -666,6 +671,11 @@ from its default.
    to instabilities that typically manifest as sliding or wobbling. The implementation of this feature depends on the
    selected convex collision pipeline, see :ref:`convex collisions<coCCD>` for more details.
 
+.. _option-flag-sleep:
+
+:at:`sleep`: :at-val:`[disable, enable], "disable"`
+   This flag enables sleeping. Feature under development, documentation pending.
+
 .. _compiler:
 
 **compiler** (*)
@@ -2059,6 +2069,11 @@ defined. Its body name is automatically defined as "world".
   equal to the body's weight and compensates for gravity exactly. Values greater than ``1`` will create a net upwards
   force or buoyancy effect.
 
+.. _body-sleep:
+
+:at:`sleep`: :at-val:`[auto, never, allowed, init], "auto"`
+   Sleep policy for the tree under this body. Feature under development, documentation pending.
+
 .. _body-user:
 
 :at:`user`: :at-val:`real(nbody_user), "0 0 ..."`