Help: Add release note for CUDA support

Help/release/dev/CUDA-language-support.rst

@@ -0,0 +1,6 @@
+CUDA-language-support
+---------------------
+
+* CMake learned to support CUDA as a first-class language.
+  It is supported by the :ref:`Makefile Generators` and the
+  :generator:`Ninja` generator.