Update README.md

Author: andrey-helldar

README.md

@@ -3,7 +3,6 @@
 ![the dragon code benchmark](https://preview.dragon-code.pro/the-dragon-code/benchmark.svg?brand=php)
 
 [![Stable Version][badge_stable]][link_packagist]
-[![Unstable Version][badge_unstable]][link_packagist]
 [![Total Downloads][badge_downloads]][link_packagist]
 [![Github Workflow Status][badge_build]][link_build]
 [![License][badge_license]][link_license]
@@ -304,8 +303,6 @@ This package is licensed under the [MIT License](LICENSE).
 
 [badge_stable]:         https://img.shields.io/github/v/release/TheDragonCode/benchmark?label=stable&style=flat-square
 
-[badge_unstable]:       https://img.shields.io/badge/unstable-dev--main-orange?style=flat-square
-
 [link_build]:           https://github.com/TheDragonCode/benchmark/actions
 
 [link_license]:         LICENSE