Create dependabot.yml

Update GitHub Actions version automatically every Monday.

.github/dependabot.yml

@@ -0,0 +1,14 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      day: "monday"
+      interval: "weekly"
+  # To be added when a package manager decision has been taken
+  # - package-ecosystem: "npm" / "pnpm" # https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#package-ecosystem