Add Build badge to readme

README.md

@@ -1,6 +1,7 @@
 # Jupyter Remote Desktop Proxy
 
 [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/jupyterhub/jupyter-remote-desktop-proxy/HEAD?urlpath=desktop)
+[![Build](https://github.com/jupyterhub/jupyter-remote-desktop-proxy/actions/workflows/build.yaml/badge.svg)](https://github.com/jupyterhub/jupyter-remote-desktop-proxy/actions/workflows/build.yaml)
 [![Latest PyPI version](https://img.shields.io/pypi/v/jupyter-remote-desktop-proxy?logo=pypi)](https://pypi.python.org/pypi/jupyter-remote-desktop-proxy)
 [![Issue tracking - GitHub](https://img.shields.io/badge/issue_tracking-github-blue?logo=github)](https://github.com/jupyterhub/jupyter-remote-desktop-proxy/issues)
 [![Help forum - Discourse](https://img.shields.io/badge/help_forum-discourse-blue?logo=discourse)](https://discourse.jupyter.org/c/jupyterhub)