Renovate configuration (#529)

* This is inspired by the default renovate config used by dxw https://github.com/dxw/renovate-config/blob/main/default.json

renovate.json

@@ -1,6 +1,27 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": [
-    "config:base"
-  ]
+    "config:recommended",
+    "group:linters",
+    "group:test",
+    "schedule:weekly",
+    ":approveMajorUpdates",
+    ":automergeLinters",
+    ":automergePatch",
+    ":automergePr",
+    ":automergeRequireAllStatusChecks",
+    ":automergeTesters",
+    ":maintainLockFilesWeekly",
+    ":dependencyDashboard"
+  ],
+  "timezone": "Europe/London",
+  "minimumReleaseAge": "7 days",
+  "automergeSchedule": ["after 10am every weekday", "before 4pm every weekday"],
+  "labels": ["dependencies", "renovate"],
+  "vulnerabilityAlerts": {
+    "addLabels": ["security"]
+  },
+  "major": {
+    "addLabels": ["major"]
+  }
 }