Add 'Cleanup Snapshot' API Documentation (#8373) (#8465)

_api-reference/snapshots/cleanup-snapshot-repository.md

@@ -0,0 +1,64 @@
+---
+layout: default
+title: Cleanup Snapshot Repository
+parent: Snapshot APIs
+nav_order: 11
+---
+
+# Cleanup Snapshot Repository 
+Introduced 1.0
+{: .label .label-purple }
+
+The Cleanup Snapshot Repository API clears a snapshot repository of data no longer referenced by any existing snapshot.
+
+## Path and HTTP methods
+
+```json
+POST /_snapshot/<repository>/_cleanup
+```
+{% include copy.html %}
+
+
+## Path parameters
+
+| Parameter | Data type | Description |
+| :--- | :--- | :--- |
+| `repository` | String | The name of the snapshot repository. |
+
+## Query parameters
+
+The following table lists the available query parameters. All query parameters are optional.
+
+| Parameter |  Data type | Description |
+| :--- | :--- | :--- |
+| `cluster_manager_timeout` | Time | The amount of time to wait for a response from the cluster manager node. Formerly called `master_timeout`. Optional. Default is 30 seconds. |
+| `timeout` | Time | The amount of time to wait for the operation to complete. Optional.|
+
+## Example request
+
+The following request removes all stale data from the repository `my_backup`:
+
+```json
+POST /_snapshot/my_backup/_cleanup
+```
+{% include copy-curl.html %}
+
+
+## Example response
+
+```json
+{
+	"results":{
+		"deleted_bytes":40,
+		"deleted_blobs":8
+	}
+}
+```
+
+## Response body fields
+
+| Field | Data type | Description |
+| :--- | :--- | :--- |
+| `deleted_bytes` | Integer | The number of bytes made available in the snapshot after data deletion. |
+| `deleted_blobs` | Integer | The number of binary large objects (BLOBs) cleared from the repository by the request. |
+