chore(docs): Updated API Reference (v2) (#8929)

Automated changes by [create-pull-request](https://github.com/peter-evans/create-pull-request) GitHub action

www/apps/api-reference/specs/admin/components/schemas/AdminCreateCampaign.yaml

@@ -0,0 +1,48 @@
+type: object
+description: The promotion's campaign.
+x-schemaName: AdminCreateCampaign
+properties:
+  name:
+    type: string
+    title: name
+    description: The campaign's name.
+  description:
+    type: string
+    title: description
+    description: The campaign's description.
+  currency:
+    type: string
+    title: currency
+    description: The campaign's currency.
+  campaign_identifier:
+    type: string
+    title: campaign_identifier
+    description: The campaign's campaign identifier.
+  starts_at:
+    type: string
+    title: starts_at
+    description: The campaign's starts at.
+    format: date-time
+  ends_at:
+    type: string
+    title: ends_at
+    description: The campaign's ends at.
+    format: date-time
+  budget:
+    type: object
+    description: The campaign's budget.
+    properties:
+      type:
+        type: string
+        description: The budget's type.
+        enum:
+          - spend
+          - usage
+      currency_code:
+        type: string
+        title: currency_code
+        description: The budget's currency code.
+      limit:
+        type: number
+        title: limit
+        description: The budget's limit.