Add Domain Locker blueprint (#308)

* Add Domain Locker blueprint with PostgreSQL backend and cron-based updater service

* Reformat "tags" arrays in meta.json to multi-line for improved readability

meta.json

@@ -1462,6 +1462,24 @@
       "document-signing"
     ]
   },
+  {
+    "id": "domain-locker",
+    "name": "Domain Locker",
+    "version": "latest",
+    "description": "Domain Locker is an open-source tool for tracking domain expirations and sending renewal reminders.",
+    "logo": "image.png",
+    "links": {
+      "github": "https://github.com/Lissy93/domain-locker",
+      "website": "https://domain-locker.com/",
+      "docs": "https://github.com/Lissy93/domain-locker#readme"
+    },
+    "tags": [
+      "domains",
+      "monitoring",
+      "utilities",
+      "postgres"
+    ]
+  },
   {
     "id": "doublezero",
     "name": "Double Zero",