Downgrade indent-string to v4.0.0 and update engines

Reverts indent-string from v5.0.0 to v4.0.0 to restore CommonJS compatibility and updates related type definitions and usage. Also updates Node.js engine requirement to >=20 and bumps hugo version in package.json.

Author: FactoryOptic

node_modules/.package-lock.json

@@ -3,7 +3,7 @@
   "description": "Doks theme",
   "version": "0.4.3",
   "engines": {
-    "node": ">=16.15.0"
+    "node": ">=20"
   },
   "browserslist": [
     "defaults"
@@ -68,6 +68,6 @@
     "stylelint-config-standard-scss": "^6.1"
   },
   "otherDependencies": {
-    "hugo": "0.99.0"
+    "hugo": "0.124.1"
   }
 }