Add dependabot

Author: kevmoo

.github/dependabot.yml

@@ -0,0 +1,11 @@
+# Set update schedule for GitHub Actions
+# See https://docs.github.com/en/code-security/supply-chain-security/keeping-your-dependencies-updated-automatically/keeping-your-actions-up-to-date-with-dependabot
+
+version: 2
+updates:
+
+- package-ecosystem: "github-actions"
+  directory: "/"
+  schedule:
+    # Check for updates to GitHub Actions every weekday
+    interval: "monthly"