Update dependabot configuration for new ecosystems

Added support for GitHub Actions and Ruby dependencies.

Author: henryiii

.github/dependabot.yml

@@ -5,7 +5,21 @@
 
 version: 2
 updates:
-  - package-ecosystem: "" # See documentation for possible values
-    directory: "/" # Location of package manifests
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "monthly"
+    groups:
+      actions:
+        patterns:
+          - "*"
+  # Maintain dependencies for Ruby
+  - package-ecosystem: "bundler"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    groups:
+      bundler:
+        patterns:
+          - "*"