add JupyterHealth to a named activity of JupyterHub team (#286)

Author: minrk

list_of_subprojects.md

@@ -11,9 +11,10 @@ The following Jupyter Subprojects have their own formal Subproject Council that
   - [JupyterLab](https://github.com/jupyterlab/jupyterlab)
   - [Jupyter Notebook](https://github.com/jupyter/notebook)
 - [JupyterHub and Binder](https://github.com/jupyterhub/team-compass)
-  - [Jupyterhub](https://github.com/jupyterhub/jupyterhub)
+  - [JupyterHub](https://github.com/jupyterhub/jupyterhub)
   - [Binder](https://github.com/jupyterhub/binder)
   - [BinderHub](https://github.com/jupyterhub/binderhub)
+  - [JupyterHealth](https://github.com/jupyterhealth)
 - [Voilà](https://voila-dashboards.github.io/)
 - [Jupyter Server](https://github.com/jupyter-server/team-compass)
   - [Jupyter Server](https://github.com/jupyter-server/jupyter_server)