frontend: add bootstrap npm package again. Turns out npm was lying to me about it not beeing used.

Author: ffreddow

frontend/package-lock.json

@@ -12,6 +12,7 @@
     "@preact/signals": "^1.2.2",
     "argon2-browser": "^1.18.0",
     "base58": "^2.0.1",
+    "bootstrap": "^5.3.3",
     "i18next": "^23.11.5",
     "i18next-browser-languagedetector": "^8.0.0",
     "i18next-http-backend": "^2.5.2",