Make model editing API public, fixes #364

Still missing:

- Detailed documentation.
- Python bindings.

PiperOrigin-RevId: 641445626
Change-Id: I20e67b707cf1bebae7e0cc94d17f7b76a89171f0

doc/APIreference/functions_override.rst

@@ -312,7 +312,7 @@ depending on which UI item was modified and what the state of that item is after
 
 This function is called in the screen refresh loop. It copies the offscreen OpenGL buffer to the window framebuffer. If
 there are multiple UIs in the application, it should be called once for each UI. Thus ``mjui_render`` is called all the
-time, while :ref:`mjui_update` is called only when changes in the UI take place.
+time, while :ref:`mjui_update` is called only when changes in the UI take place. dsffsdg
 
 
 
@@ -545,7 +545,7 @@ Finite-differenced discrete-time transition matrices.
 
 Letting :math:`x, u` denote the current :ref:`state<gePhysicsState>` and :ref:`control<geInput>`
 vector in an mjData instance, and letting :math:`y, s` denote the next state and sensor
-values, the top-level :ref:`mj_step` function computes :math:`(x,u) \rightarrow (y,s)`.
+values, the top-level :ref:`mj_step` function computes :math:`(x,u) \rightarrow (y,s)`
 :ref:`mjd_transitionFD` computes the four associated Jacobians using finite-differencing.
 These matrices and their dimensions are:
 
@@ -623,3 +623,8 @@ to the inputs. Below, :math:`\bar q` denotes the pre-modified quaternion:
 
 Note that derivatives depend only on :math:`h` and :math:`v` (in fact, on :math:`s = h v`).
 All outputs are optional.
+
+.. _SpecManip:
+
+These functions provide high level manipulation for :ref:`mjSpec` structs, which represent an uncompiled :ref:`mjModel`.
+