Add default config

README.md

@@ -1,2 +1,23 @@
 # renovate-config
 Shared configurations for Renovate bot
+
+Use as [described in the Renovate docs](https://docs.renovatebot.com/config-presets/):
+
+```json
+{
+  "extends": ["github>AmpelProject/renovate-config"]
+}
+```
+
+## default
+
+This is intended to keep noise down while upgrading Ampel-internal dependencies as rapidly as possible.
+
+Monthly:
+- minor and patch updates to install dependencies are grouped together, and automatically merged when tests pass
+- ditto for dev dependencies
+- major updates create individual PRs
+
+Every run:
+- Ampel packages are bumped
+

default.json

@@ -0,0 +1,32 @@
+{
+  "extends": [
+    "config:base"
+  ],
+  "schedule": "every 1 month on Monday before 5am",
+  "automerge": true,
+  "automergeType": "branch",
+  "lockFileMaintenance": {
+    "enabled": true
+  },
+  "packageRules": [
+    {
+      "matchUpdateTypes": ["minor", "patch", "pin", "digest"],
+      "groupName": "minor updates"
+    },
+    {
+      "matchUpdateTypes": ["major"],
+      "automerge": false
+    },
+    {
+      "matchDepTypes": ["dev-dependencies"],
+      "groupName": "dev dependencies",
+      "rangeStrategy": "bump"
+    },
+    {
+      "matchPackagePatterns": ["^ampel-.*"],
+      "schedule": null,
+      "groupName": "ampel packages",
+      "rangeStrategy": "bump"
+    }
+  ]
+}