docs: add demo link

TheAlexLichter · TheAlexLichter · commit d2bf36546954 · 2018-10-14T13:07:21.000+01:00
diff --git a/README.md b/README.md
@@ -24,6 +24,9 @@
 
 ## :mag_right: Getting started
 
+### :star: Demo
+
+A live demo is available at [https://oqxy5xr5ny.sse.codesandbox.io/](https://oqxy5xr5ny.sse.codesandbox.io/).
 
 ### :package: Through NPM
 
