Configure Renovate (#23)

Co-authored-by: Gregor Harlan <mail@gh01.de>

.github/renovate.json

@@ -0,0 +1,16 @@
+{
+    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+    "extends": [
+        "config:best-practices",
+        ":timezone(Europe/Berlin)",
+        ":disableDependencyDashboard",
+        ":semanticCommitsDisabled"
+    ],
+    "packageRules": [
+        {
+            "matchManagers": ["github-actions"],
+            "groupName": "actions",
+            "schedule": ["on the first day of the month"]
+        }
+    ]
+}