docs: remove gitter from index

Author: egil

docs/site/index.md

@@ -6,7 +6,6 @@ title: bUnit - a testing library for Blazor components
 [![GitHub tag (latest SemVer pre-release)](https://img.shields.io/github/v/tag/egil/bunit?include_prereleases&logo=github&style=flat-square)](https://github.com/egil/bunit/releases)
 [![Nuget](https://img.shields.io/nuget/dt/bunit?logo=nuget&style=flat-square)](https://www.nuget.org/packages/bunit/)
 [![Issues Open](https://img.shields.io/github/issues/egil/bunit.svg?style=flat-square&logo=github)](https://github.com/egil/bunit/issues)
-[![Gitter](https://img.shields.io/gitter/room/egil/bunit?logo=gitter&style=flat-square)](https://gitter.im/egil/bunit?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 
 # bUnit: a testing library for Blazor components