Remove gitter badge
</h2>
<p align="center">
- <a href="https://gitter.im/reviewdog/reviewdog?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge">
- <img alt="Gitter" src="https://img.shields.io/badge/chat-gitter-1DCE73.svg?label=chat&maxAge=43200">
- </a>
<a href="https://github.com/reviewdog/reviewdog/blob/master/LICENSE">
<img alt="LICENSE" src="https://img.shields.io/badge/license-MIT-blue.svg?maxAge=43200">
</a>
