Bump Monaco 0.18.1, fixes deadlock with Edge Legacy

Playground/package.json

@@ -9,7 +9,7 @@
   "readme": "https://github.com/BabylonJS/Babylon.js/blob/master/readme.md",
   "license": "(Apache-2.0)",
   "devDependencies": {
-    "monaco-editor": "~0.10.1"
+    "monaco-editor": "~0.18.1"
   },
   "scripts": {
     "test": "browser-sync start --server --files **/* --no-inject-changes --startPath index.html"