Update tutorials tables of content for several modules

doc/tutorials/gpu/table_of_content_gpu.markdown

@@ -6,6 +6,8 @@ run the OpenCV algorithms.
 
 -   @subpage tutorial_gpu_basics_similarity
 
+    *Languages:* C++
+
     *Compatibility:* \> OpenCV 2.0
 
     *Author:* Bernát Gábor
@@ -16,6 +18,8 @@ run the OpenCV algorithms.
 
 -   @subpage tutorial_gpu_thrust_interop
 
+    *Languages:* C++
+
     *Compatibility:* \>= OpenCV 3.0
 
     This tutorial will show you how to wrap a GpuMat into a thrust iterator in order to be able to