update docs for use_bvh option in stl (!99)

docs/source_docs/user_guide/inputs/geometry.rst

@@ -376,6 +376,8 @@ The following inputs are defined using the ``stl`` prefix.
 +------------------------+-------------------------------------------------------------------+----------+---------------------+
 | translation            | translate the geometry                                            | Reals    | 0. 0. 0.            |
 +------------------------+-------------------------------------------------------------------+----------+---------------------+
+| use_bvh                | Use bounding volume optimization                                  | Bool     | True                |
++------------------------+-------------------------------------------------------------------+----------+---------------------+
 
 .. note::
    A full description of this feature is beyond the scope of this section. A future update to