Configure dependabot for nested package.json files (#458)

.github/dependabot.yml

@@ -5,11 +5,23 @@
 
 version: 2
 updates:
-  - package-ecosystem: "npm" # See documentation for possible values
-    directory: "/" # Location of package manifests
+  - package-ecosystem: "npm"
+    directory: "/"
     schedule:
       interval: "weekly"
-    open-pull-requests-limit: 20
+    open-pull-requests-limit: 3
+    versioning-strategy: increase
+  - package-ecosystem: "npm"
+    directory: "/platform/android"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 3
+    versioning-strategy: increase
+  - package-ecosystem: "npm"
+    directory: "/platform/ios"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 3
     versioning-strategy: increase
   - package-ecosystem: 'github-actions'
     directory: '/'