enable dependabot

Signed-off-by: Bohan Chen <bohanc@vmware.com>

Author: Bohan Chen

.github/dependabot.yml

@@ -0,0 +1,13 @@
+version: 2
+updates:
+  # Dependencies listed in go.mod
+  - package-ecosystem: "gomod"
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "weekly"
+
+  # Dependencies listed in .github/workflows/*.yml
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"