add dependabot config

Author: sunshowers

.github/dependabot.yml

@@ -0,0 +1,11 @@
+# Reference:
+# https://docs.github.com/en/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "cargo"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    allow:
+      - dependency-type: all