revert typedoc to a previous version

fixes our failed CI runs like https://github.com/supabase/supabase-js/runs/2673094175

Author: inian

package-lock.json

@@ -51,7 +51,7 @@
     "rimraf": "^3.0.2",
     "ts-jest": "^26.3.0",
     "ts-loader": "^8.0.11",
-    "typedoc": "^0.20.36",
+    "typedoc": "^0.19.1",
     "typescript": "^4.0.2",
     "webpack": "^5.4.0",
     "webpack-cli": "^4.2.0"