chore: update the kotlin playground version

AlexanderPrendota · AlexanderPrendota · commit e0843a5016a1 · 2018-06-15T10:10:25.000+03:00
diff --git a/_layouts/default.html b/_layouts/default.html
@@ -33,7 +33,7 @@
     <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
     <![endif]-->
 
-    <script src="https://unpkg.com/kotlin-runcode@1.0.18/dist/runcode.min.js" data-selector=".language-kotlin"></script>
+    <script src="https://unpkg.com/kotlin-playground@1" data-selector=".language-kotlin"></script>
 </head>
 
 <body>
