Update dependabot to run monthly + batch updates

Author: mheap

.github/dependabot.yml

@@ -3,4 +3,15 @@ updates:
   - package-ecosystem: "npm"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "monthly"
+    groups:
+      production-dependencies:
+        dependency-type: "production"
+        update-types:
+          - "minor"
+          - "patch"
+      development-dependencies:
+        dependency-type: "development"
+        update-types:
+          - "minor"
+          - "patch"