update docs

README.md

@@ -1,6 +1,6 @@
 <p align="center">
   <a href="https://growi.org">
-    <img src="https://user-images.githubusercontent.com/42988650/70600974-6b29cc80-1c34-11ea-94ef-33c39c6a00dc.gif" width="240px">
+    <img src="https://user-images.githubusercontent.com/1638767/38254268-d4476bbe-3793-11e8-964c-8865d690baff.png" width="240px">
   </a>
 </p>
 <p align="center">
@@ -24,6 +24,8 @@ GROWI
 [![devDependencies Status](https://david-dm.org/weseek/growi/dev-status.svg)](https://david-dm.org/weseek/growi?type=dev)
 [![docker pulls](https://img.shields.io/docker/pulls/weseek/growi.svg)](https://hub.docker.com/r/weseek/growi/)
 
+![sample image](https://user-images.githubusercontent.com/42988650/70600974-6b29cc80-1c34-11ea-94ef-33c39c6a00dc.gif)
+
 - [Features](#features)
 - [Quick Start for Production](#quick-start-for-production)
     - [Heroku](#heroku)
@@ -33,7 +35,6 @@ GROWI
 - [Documentation](#documentation)
 - [License](#license)
 
-
 Features
 ========