Add cooldown and groups configuration for Dependabot

Author: twwd

.github/dependabot.yml

@@ -9,7 +9,17 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+    cooldown:
+      default-days: 3
+      semver-major-days: 7
+      semver-minor-days: 3
+      semver-patch-days: 3
   - package-ecosystem: "github-actions"
     directory: ".github"
+    cooldown:
+      default-days: 3
     schedule:
       interval: "weekly"
+    groups:
+      all-actions:
+        patterns: [ "*" ]