Add api-ref about quotas-delete

1.Add api-ref about quotas-delete;
2.Update sample of quotas-update.

Closes-Bug:#1698111
Change-Id: I435a80da7efe9c898782b8eab8744db80928c9c1

api-ref/source/quotas.inc

@@ -95,7 +95,7 @@ Update a resource quota
 
 .. rest_method:: PATCH /v1/quotas/{project_id}/{resource}
 
-Update resource quota for the given projec id.
+Update resource quota for the given project id.
 
 Response Codes
 --------------
@@ -122,3 +122,30 @@ Response Example
 
 .. literalinclude:: samples/quota-update-resp.json
    :language: javascript
+
+Delete a resource quota
+============================
+
+.. rest_method:: DELETE /v1/quotas/{project_id}/{resource}
+
+Delete a resource quota for the given project id.
+
+Response Codes
+--------------
+
+.. rest_status_code:: success status.yaml
+
+   - 204
+
+.. rest_status_code:: error status.yaml
+
+   - 400
+   - 401
+   - 403
+   - 404
+
+Request Example
+----------------
+
+.. literalinclude:: samples/quota-delete-req.json
+   :language: javascript

api-ref/source/samples/quota-delete-req.json

@@ -0,0 +1,4 @@
+{
+   "project_id": "aa5436ab58144c768ca4e9d2e9f5c3b2",
+   "resource": "Cluster"
+}

api-ref/source/samples/quota-update-req.json

@@ -1,3 +1,5 @@
 {
+   "project_id": "aa5436ab58144c768ca4e9d2e9f5c3b2",
+   "resource": "Cluster",
    "hard_limit": 10
 }