Use JupyterLite for the C++ demo (#807)

Author: jtpio

try.html

@@ -55,8 +55,8 @@
     - title: C++
       description: How to use Jupyter with C++
       src: try/Cpp.svg
-      alt: C++ logo - Launch C++ demo Binder
-      url: https://mybinder.org/v2/gh/jupyter-xeus/xeus-cling/stable?filepath=notebooks/xcpp.ipynb
+      alt: C++ logo - Launch C++ demo
+      url: https://jupyter.org/try-jupyter/lab/index.html?path=notebooks%2Fcpp.ipynb
 
     - title: Julia
       description: How to use Jupyter with Julia