Update README.md to say Studio instead of sandbox

Author: epost

README.md

@@ -1,13 +1,10 @@
-# Statebox sandbox in PureScript
+# Statebox Studio
 
-https://heuristic-swartz-dd8481.netlify.com/
+## Try online
 
-This is a sandbox/incubator project for some PureScript Statebox code containing:
+https://statebox-studio-test.netlify.com/
 
-- A basic animated interactive Petrinet viewer.
-- Some types and implementations to make things tick.
-
-# Build and run
+## Build and run
 
 Clone and `cd` into the repo, then do:
 ```