Add details for the document for review

Author: noah

docs/concepts/review.md

@@ -2,11 +2,23 @@
 
 Gitploy has the review to require at least one approval for the deployment. You can list up to users on the configuration file. The reviewers must have at least read access to the repository. 
 
+## Review process
+
+1. First, to enable review, you must configure like the below:
+
 ```yaml
 envs:
   - name: production
     auto_merge: true
     review:
       enabled: true
-      reviewers: ["octocat", "noah"]
+      reviewers: ["YOUR_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)