message: add a small excerpt on the existence of OSPRay tutorial apps
diff: Examples
  ========
  -Tutorial
  ---------
  +Simple Tutorial
  +---------------
  A minimal working example demonstrating how to use OSPRay can be found
  at `apps/ospTutorial.c`^[A C++ version that uses the C++ convenience
  @@ -30,6 +30,24 @@ frames in the second image `accumulatedFrames.ppm`.
  ![After accumulating ten frames.][imgTutorial2]
  +Mini-App Tutorials
  +------------------
  +
  +OSPRay also ships various mini-apps to showcase OSPRay features. These
  +apps are all prefixed with `ospTutorial` and can be found in the
  +`tutorials/` directory of the OSPRay source tree. Current tutorials
  +include:
  +
  +- structured volumes
  +- unstructured volumes
  +- spheres
  +- animated spheres
  +- subdivision surfaces
  +
  +More apps will be created in future releases to further demonstrate
  +other interesting OSPRay features.
  +
  +
  Example Viewer
  --------------
  