Add future property to simpleconfig stub (#2372)

* Add future property to simpleconfig stub

* Add future flags manually

Author: dextermb

stubs/simpleConfig.stub.js

@@ -1,8 +1,12 @@
 module.exports = {
   purge: [],
+  plugins: [],
   theme: {
     extend: {},
   },
+  future: {
+    // removeDeprecatedGapUtilities: true,
+    // purgeLayersByDefault: true,
+  },
   variants: {},
-  plugins: [],
 }