feat: add dependabot

Fixes #1118.
Adds `dependabot.yml` to `.github/` to check for `"github-action"`
updates on a `"weekly"` basis.
This does not touch Rust code or Cargo workflows.

It will  create PRs and we would need to approve them
(they would be subject to the same merge policy)
to instantiate the proposed dependabots into `master`.

diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644 (file)
index 0000000..453228e
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,8 @@
+# Set update schedule for GitHub Actions
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every week
+      interval: "weekly"