fix: pin ts to 4.0.x (#683)

Author: hugomrdias

package.json

@@ -115,7 +115,7 @@
     "strip-json-comments": "^3.1.1",
     "terser-webpack-plugin": "^3.0.5",
     "typedoc": "^0.19.2",
-    "typescript": "^4.0.5",
+    "typescript": "4.0.x",
     "update-notifier": "^5.0.0",
     "webpack": "^4.43.0",
     "webpack-bundle-analyzer": "^3.7.0",