Fix the document for review (#212)

Author: Noah Hanjun Lee

docs/concepts/review.md

@@ -12,13 +12,7 @@ envs:
     auto_merge: true
     review:
       enabled: true
-      reviewers: ["YOUR_LOGIN"]
+      reviewers: ["USER_LOGIN"]
 ```
 
-2\. When the user deploys, Gitploy request a review to reviewers.
-
-![review](../images/deploy-with-review.png)
-
-3\. After deploy, reviewers check what is changes and review the deployment. 
-
-![review](../images/review.png)
+2\. When the user deploys, Gitploy request a review to reviewers. And the deployment is waiting until one of reviews is approved.