Add shared "check renovatebot config" action

Author: Joonas Hiltunen

.github/workflows/shared-check-renovatebot-config.yml

@@ -0,0 +1,29 @@
+name: Shared check renovatebot config
+
+on:
+  workflow_call:
+    inputs:
+      config_file_path:
+        description: Path to the Renovatebot config file to validate
+        type: string
+        required: true
+      checkout_submodules:
+        description: Whether to checkout submodules
+        type: string
+        required: false
+        default: "false"
+
+jobs:
+  validate:
+    name: Validate renovatebot config
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          submodules: ${{ inputs.checkout_submodules }}
+
+      - name: Validate config
+        uses: suzuki-shunsuke/github-action-renovate-config-validator@c22827f47f4f4a5364bdba19e1fe36907ef1318e # v1.1.1
+        with:
+          config_file_path: ${{ inputs.config_file_path }}

README.md

@@ -294,10 +294,11 @@ onboarding flow ends.
 
 Example:
 ```
-- name: Validate
-  uses: suzuki-shunsuke/github-action-renovate-config-validator@v0.1.3
-  with:
-    config_file_path: .github/renovate.json5
+jobs:
+  validate:
+    uses: HSLdevcom/jore4-tools/.github/workflows/shared-check-renovatebot-config.yml@shared-check-renovatebot-config-v1
+    with:
+      config_file_path: renovatebot/jore4-default-preset.json5
 ```
 
 To see a bit more in detail how the renovatebot rules work, check the comments within the