Add dependabot config

Author: smerrell

.github/dependabot.yml

@@ -0,0 +1,10 @@
+# https://docs.github.com/en/github/administering-a-repository/keeping-your-dependencies-updated-automatically
+version: 2
+updates:
+  # Enable version updates for Docker
+  - package-ecosystem: "docker"
+    # Look for a `Dockerfile` in the `root` directory
+    directory: "/"
+    # Check for updates once a week
+    schedule:
+      interval: "weekly"