Added black hole raytracing example image

examples/images/README.md

@@ -2,6 +2,9 @@ This file provides the necessary redirections to the appropriate license
 information for the images under the folder `examples/images` in
 [this](https://github.com/arrayfire/assets) repository.
 
+* <img width="128" alt="Westerlund 2 space image" src="westerlund.jpg"> Westerlund 2 Image from ASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team. See
+http://www.spacetelescope.org/images/heic1509a/ for details. This file is licensed under the [Creative Commons](https://en.wikipedia.org/wiki/Creative_Commons) [Attribution 4.0 International](https://creativecommons.org/licenses/by/4.0/) license.
+
 * <a title="By Power3d (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons" href="https://commons.wikimedia.org/wiki/File%3ALovely_spider.jpeg"><img width="128" alt="Lovely spider" src="https://upload.wikimedia.org/wikipedia/commons/thumb/b/b3/Lovely_spider.jpeg/512px-Lovely_spider.jpeg"/></a> spider.jpg - This file is licensed under the [Creative Commons](https://en.wikipedia.org/wiki/Creative_Commons) [Attribution-Share Alike 3.0 Unported](https://creativecommons.org/licenses/by-sa/3.0/deed.en) license.
 * <a title="By NASA [Public domain], via Wikimedia Commons" href="https://commons.wikimedia.org/wiki/File:ISS_from_Atlantis_-_Sts101-714-016.jpg"><img width="128" alt="ISS from Atlantis - Sts101-714-016" src="https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/ISS_from_Atlantis_-_Sts101-714-016.jpg/512px-ISS_from_Atlantis_-_Sts101-714-016.jpg"/></a> atlantis.png - This image or video was catalogued by Johnson Space Center of the United States National Aeronautics and Space Administration (NASA) under Photo ID: STS101-714-016. 
 * <a title="By http://www.freephotos.lu/ [CC BY 1.0 (http://creativecommons.org/licenses/by/1.0)], via Wikimedia Commons" href="https://commons.wikimedia.org/wiki/File:Image_processing_pre_otsus_algorithm.jpg"><img width="128" alt="Image processing pre otsus algorithm" src="https://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Image_processing_pre_otsus_algorithm.jpg/512px-Image_processing_pre_otsus_algorithm.jpg"/></a> house.jpg - This file is licensed under the [Creative Commons](https://en.wikipedia.org/wiki/Creative_Commons) [Attribution 1.0 Generic](https://creativecommons.org/licenses/by/1.0/deed.en) license.