docs: add online link to README
@@ -4,6 +4,8 @@ The **C**OVID-19 **H**ospital **I**mpact **M**odel for **E**pidemics
[![CHIME](https://user-images.githubusercontent.com/1069047/76693244-5e07e980-6638-11ea-9e02-1c265c86fd2b.gif)](http://predictivehealthcare.pennmedicine.org/chime)
+Try it out online at [penn-chime.phl.io](http://penn-chime.phl.io/)
+
Interested in [contributing](https://codeforphilly.github.io/chime/CONTRIBUTING.html)?
Join our [Code For Philly](https://codeforphilly.org/projects/chime) project or our [Slack workspace](https://codeforphilly.org/chat) in the [#covid19-chime-penn](https://codeforphilly.org/chat/covid19-chime-penn) channel if you'd like to chat with us. We'd appreciate your [feedback](http://predictivehealthcare.pennmedicine.org/contact/).
