README: update headline and preview

[CI SKIP]

README.md

@@ -1,14 +1,8 @@
-# Gogs
+# <img src="public/img/favicon.png" width="45" align="left">Gogs - A painless self-hosted Git service
 
 [![Build status](https://img.shields.io/travis/gogs/gogs/master.svg?style=for-the-badge&logo=travis)](https://travis-ci.org/gogs/gogs) [![Build status](https://img.shields.io/appveyor/ci/Unknwon/gogs?logo=appveyor&style=for-the-badge)](https://ci.appveyor.com/project/Unknwon/gogs/branch/master) [![Discord](https://img.shields.io/discord/382595433060499458.svg?style=for-the-badge&logo=discord)](https://discord.gg/9aqdHU7) [![Sourcegraph](https://img.shields.io/badge/view%20on-Sourcegraph-brightgreen.svg?style=for-the-badge&logo=sourcegraph)](https://sourcegraph.com/github.com/gogs/gogs)
 
-![](https://github.com/gogs/gogs/blob/master/public/img/gogs-large-resize.png?raw=true)
+![Repository](https://gogs.io/img/screenshots/2.png)
-
-| Web | UI  | Preview  |
-|:-------------:|:-------:|:-------:|
-|![Dashboard](https://gogs.io/img/screenshots/1.png)|![Repository](https://gogs.io/img/screenshots/2.png)|![Editor](https://gogs.io/img/screenshots/3.png)|
-|![Profile](https://gogs.io/img/screenshots/4.png)|![Diff](https://gogs.io/img/screenshots/5.png)|![Repository Settings](https://gogs.io/img/screenshots/6.png?ts=20170322)|
-|![Webhook](https://gogs.io/img/screenshots/7.png)|![Organization](https://gogs.io/img/screenshots/8.png)|![Admin Dashboard](https://gogs.io/img/screenshots/9.png)|
 
 ### ⚠️ Important notes ⚠️