Enable renovate

renovate.json

+{
+  "branchPrefix": "renovate/",
+  "username": "renovate-release",
+  "gitAuthor": "Renovate Bot <bot@renovateapp.com>",
+  "platform": "gitlab",
+  "separateMajorMinor": true,
+  "extends": [
+    ":preserveSemverRanges",
+    "group:all",
+    ":maintainLockFilesMonthly"
+  ],
+  "packageRules": [
+    {
+      "matchPackageNames": [
+        "highlight.js",
+        "highlightjs-line-numbers.js"
+      ],
+      "matchUpdateTypes": [
+        "major"
+      ],
+      "enabled": false
+    }
+  ],
+  "lockFileMaintenance": {
+    "extends": [
+      "group:all"
+    ],
+    "commitMessageAction": "Update"
+  }
+}