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/CollectionsResource.md

@@ -0,0 +1,53 @@
+# Class: CollectionsResource
+
+## Hierarchy
+
+- `default`
+
+  ↳ **`CollectionsResource`**
+
+## Methods
+
+### list
+
+▸ **list**(`query?`, `customHeaders?`): [`ResponsePromise`](../modules/internal.md#responsepromise)<[`StoreCollectionsListRes`](../modules/internal.md#storecollectionslistres)\>
+
+**`description`** Retrieves a list of collections
+
+#### Parameters
+
+| Name | Type | Description |
+| :------ | :------ | :------ |
+| `query?` | [`StoreGetCollectionsParams`](internal.StoreGetCollectionsParams.md) | is optional. Can contain a limit and offset for the returned list |
+| `customHeaders` | [`Record`](../modules/internal.md#record)<`string`, `any`\> |  |
+
+#### Returns
+
+[`ResponsePromise`](../modules/internal.md#responsepromise)<[`StoreCollectionsListRes`](../modules/internal.md#storecollectionslistres)\>
+
+#### Defined in
+
+[packages/medusa-js/src/resources/collections.ts:28](https://github.com/medusajs/medusa/blob/2eb2126f/packages/medusa-js/src/resources/collections.ts#L28)
+
+___
+
+### retrieve
+
+▸ **retrieve**(`id`, `customHeaders?`): [`ResponsePromise`](../modules/internal.md#responsepromise)<[`StoreCollectionsRes`](../modules/internal.md#storecollectionsres)\>
+
+**`description`** Retrieves a single collection
+
+#### Parameters
+
+| Name | Type | Description |
+| :------ | :------ | :------ |
+| `id` | `string` | id of the collection |
+| `customHeaders` | [`Record`](../modules/internal.md#record)<`string`, `any`\> |  |
+
+#### Returns
+
+[`ResponsePromise`](../modules/internal.md#responsepromise)<[`StoreCollectionsRes`](../modules/internal.md#storecollectionsres)\>
+
+#### Defined in
+
+[packages/medusa-js/src/resources/collections.ts:17](https://github.com/medusajs/medusa/blob/2eb2126f/packages/medusa-js/src/resources/collections.ts#L17)