Remove use of vercel for demo deployment (#69)

Author: ianthomas23

README.md

@@ -1,7 +1,7 @@
 # jupyterlite-terminal
 
 [![Github Actions Status](https://github.com/jupyterlite/terminal/workflows/Build/badge.svg)](https://github.com/jupyterlite/terminal/actions/workflows/build.yml)
-[![lite-badge](https://jupyterlite.rtfd.io/en/latest/_static/badge.svg)](https://jupyterlite-terminal.vercel.app/)
+[![lite-badge](https://jupyterlite.rtfd.io/en/latest/_static/badge.svg)](https://jupyterlite.github.io/terminal/)
 
 A terminal for JupyterLite.