chore(docs): patch dependabot vulns via npm overrides

- Override serialize-javascript to ^7.0.5 (fixes CVE GHSA-76p7-773f-r4q5
  RCE and GHSA-xxx CPU exhaustion DoS in transitive deps from
  copy-webpack-plugin and css-minimizer-webpack-plugin)
- Override postcss to ^8.5.10 (fixes XSS via unescaped </style>)
- npm audit now reports 0 vulnerabilities

Author: MDUYN

docusaurus/package-lock.json

@@ -29,6 +29,10 @@
   "devDependencies": {
     "@docusaurus/module-type-aliases": "3.9.2"
   },
+  "overrides": {
+    "serialize-javascript": "^7.0.5",
+    "postcss": "^8.5.10"
+  },
   "browserslist": {
     "production": [
       ">0.5%",