Update dependency typedoc to v0.21.6

Author: renovate-bot

package-lock.json

@@ -67,7 +67,7 @@
     "tslint": "5.20.1",
     "tslint-clean-code": "0.2.10",
     "tslint-microsoft-contrib": "6.2.0",
-    "typedoc": "0.21.5",
+    "typedoc": "0.21.6",
     "typescript": "3.9.10"
   },
   "dependencies": {