Add Qt to the license list - using LGPL 2.1

LICENSE.md

@@ -85,3 +85,7 @@ RenderDoc also uses several external libraries and components which include thei
 - [glslang](https://github.com/KhronosGroup/glslang)
   distributed under the New BSD License (3 Clause).
   Copyright 2002-2005 3Dlabs Inc. Ltd. 2012-2013 LunarG, Inc.
+
+- [Qt](http://www.qt.io/)
+  distributed under the GNU Lesser General Public License (LGPL) version 2.1
+  Copyright 2015 The Qt Company Ltd.

docs/Credits.aml

@@ -134,7 +134,15 @@
 <linkUri>https://github.com/KhronosGroup/glslang</linkUri>
 </externalLink>
   </para></listItem>
-  
+
+  <listItem><para>
+  <externalLink>
+<linkText>Qt</linkText>
+<linkAlternateText>Used for QRenderDoc replay UI program</linkAlternateText>
+<linkUri>http://www.qt.io/</linkUri>
+</externalLink>
+  </para></listItem>
+
   <listItem><para>
   <externalLink>
 <linkText>Sandcastle Help File Builder</linkText>