Add ktx

ktx/LICENSES/LicenseRef-PNGSuite.txt

@@ -0,0 +1,14 @@
+The following text is copied and pasted from
+http://www.schaik.com/pngsuite/PngSuite.LICENSE , which is the license under
+which an image from the PngSuite project is used. Please refer to the
+original link as the authoritative text; this file exists only for REUSE
+license-checker compliance.
+
+PngSuite
+--------
+
+Permission to use, copy, modify and distribute these images for any
+purpose and without fee is hereby granted.
+
+
+(c) Willem van Schaik, 1996, 2011