Merge pull request #2697 from mati-nvidia/mati/usdSkel_docs

Improve UsdSkel docs

(Internal change: 2308060)

diff --cc pxr/usd/usdSkel/doxygen/schemas.dox
index 122fd300585803d63376b82931dcdaec55181dd9,46f9e30b25d6d5e79979015a2086b22fee125845..f229d53d3713c5d6c9e6820cd6a220ac207bb0d7
--- 1/pxr/usd/usdSkel/doxygen/schemas.dox
--- 2/pxr/usd/usdSkel/doxygen/schemas.dox
+++ b/pxr/usd/usdSkel/doxygen/schemas.dox
@@@ -535,7 -584,10 +584,10 @@@ the joint indices refer to the orderin
  indices refer to joints `A/B` and `A`, respectively. However, `</MeshB>`
  specifies a `skel:joints` property that gives an alternate joint ordering.
  Using that, the indices of `</MeshB>` refer to joints `A/B/C` and `A/B`,
- in that order.
 -in that order. Note that the joints specified for _skel:joints_ can be a subset 
 -of the joints defined on the bound Skeleton. Also, _skel:joints_ does not need
 -to adhere to the parents before children ordering mentioned in 
 -\ref UsdSkel_JointHierarchy "joint hierarchy."
++in that order. Note that the joints specified for _skel:joints_ on the bound 
++prims can be a subset of the joints defined on the bound Skeleton. Also, 
++_skel:joints_ does not need to adhere to the parents before children ordering 
++mentioned in \ref UsdSkel_JointHierarchy "joint hierarchy."
  
  In the common case, the joint influence primvars are configured with _vertex_
  interpolation, and define a fixed number of contiguous influences per point.