Switch to monthly dependabot updates

Author: TonyRippy

.github/dependabot.yml

@@ -1,17 +1,20 @@
 # Please see the documentation for all configuration options:
-# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+# https://docs.github.com/en/code-security/dependabot/working-with-dependabot/dependabot-options-reference
 
 version: 2
 updates:
   - package-ecosystem: "cargo"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "monthly"
     groups:
       minor-updates:
         applies-to: version-updates
         update-types: [minor, patch]
+      major-updates:
+        applies-to: version-updates
+        update-types: [major]
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "monthly"