chore: reorganize docs apps (#7228)

* reorganize docs apps

* add README

* fix directory

* add condition for old docs

www/apps/resources/references/promotion/interfaces/promotion.CreateCampaignBudgetDTO/page.mdx

@@ -0,0 +1,11 @@
+---
+displayed_sidebar: promotionReference
+---
+
+import { TypeList } from "docs-ui"
+
+# CreateCampaignBudgetDTO
+
+The campaign budget to be created.
+
+<TypeList types={[{"name":"type","type":"[CampaignBudgetTypeValues](../../types/promotion.CampaignBudgetTypeValues/page.mdx)","description":"The type of the campaign budget.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"limit","type":"`null` \\| `number`","description":"The limit of the campaign budget.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"used","type":"`number`","description":"How much is used of the campaign budget.","optional":true,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="CreateCampaignBudgetDTO"/>