chore: add renovate config

renovate.json5

@@ -0,0 +1,19 @@
+{
+  $schema: 'https://docs.renovatebot.com/renovate-schema.json',
+  extends: [
+    'config:recommended',
+    'customManagers:helmChartYamlAppVersions',
+    'helpers:pinGitHubActionDigests',
+  ],
+  customManagers: [
+    {
+      customType: "regex",
+      fileMatch: ['\\.github/workflows/release.ya?ml'],
+      matchStrings: [
+        // this is mostly a copy from https://docs.renovatebot.com/presets-customManagers/#custommanagersgithubactionsversions
+        // and only changes the expected version prefix
+        "# renovate: datasource=(?<datasource>[a-z-.]+?) depName=(?<depName>[^\\s]+?)(?: (?:lookupName|packageName)=(?<packageName>[^\\s]+?))?(?: versioning=(?<versioning>[^\\s]+?))?(?: extractVersion=(?<extractVersion>[^\\s]+?))?\\s+[A-Za-z0-9_]+?version\\s*:\\s*[\"']?(?<currentValue>.+?)[\"']?\\s"
+      ]
+    }
+  ]
+}