add dependabot config

Dependabot config matches the latest config from the controller library.

Signed-off-by: Blaine Gardner <[email protected]>

Author: BlaineEXE

Diff for: .github/dependabot.yml

@@ -0,0 +1,27 @@
+version: 2
+enable-beta-ecosystems: true
+updates:
+
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    groups: # batch updates together for fewer dependabot PRs
+      golang-dependencies:
+        patterns:
+          - "github.com/golang*"
+      k8s-dependencies:
+        patterns:
+          - "k8s.io*"
+          - "sigs.k8s.io*"
+        exclude-patterns:
+          # controller-runtime has history of breaking API changes more often than other k8s projects
+          - "sigs.k8s.io/controller-runtime"
+      github-dependencies:
+        patterns:
+          - "github.com*"
+
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "weekly"