message: add excerpt about OIDN in the example viewer
diff: @@ -121,6 +121,13 @@ viewer.
  * Supported file importers currently include: `obj`, `ply`, `x3d`,
  `vtu`, `osp`, `ospsg`, `xml` (rivl), `points`, `xyz`.
  +### Denoiser
  +
  +When the example viewer is built with OpenImageDenoise, the denoiser is
  +automatically enabled when running the application. It can be toggled
  +on/off at runtime via the `useDenoiser` GUI parameter found under the
  +framebuffer in the scene graph.
  +
  Distributed Viewer
  ------------------
  