docs: added reference for JS Client (#1629)

* added reference for JS Client

* added reference for JS Client

* added reference for JS Client

docs/content/references/js-client/classes/GiftCardsResource.md

@@ -0,0 +1,30 @@
+# Class: GiftCardsResource
+
+## Hierarchy
+
+- `default`
+
+  ↳ **`GiftCardsResource`**
+
+## Methods
+
+### retrieve
+
+▸ **retrieve**(`code`, `customHeaders?`): [`ResponsePromise`](../modules/internal.md#responsepromise)<[`StoreGiftCardsRes`](../modules/internal.md#storegiftcardsres)\>
+
+**`description`** Retrieves a single GiftCard
+
+#### Parameters
+
+| Name | Type | Description |
+| :------ | :------ | :------ |
+| `code` | `string` | code of the gift card |
+| `customHeaders` | [`Record`](../modules/internal.md#record)<`string`, `any`\> |  |
+
+#### Returns
+
+[`ResponsePromise`](../modules/internal.md#responsepromise)<[`StoreGiftCardsRes`](../modules/internal.md#storegiftcardsres)\>
+
+#### Defined in
+
+[packages/medusa-js/src/resources/gift-cards.ts:12](https://github.com/medusajs/medusa/blob/2eb2126f/packages/medusa-js/src/resources/gift-cards.ts#L12)