Remove stable documentation badge from README

Author: shawn-tao01

README.md

@@ -1,6 +1,6 @@
 # JuDO
 
-[![Stable](https://img.shields.io/badge/docs-stable-blue.svg)](https://JuDO-dev.github.io/JuDO.jl/stable/)
+
 [![Dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://JuDO-dev.github.io/JuDO.jl/dev/)
 [![Build Status](https://github.com/JuDO-dev/JuDO.jl/actions/workflows/CI.yml/badge.svg?branch=dev)](https://github.com/JuDO-dev/JuDO.jl/actions/workflows/CI.yml?query=branch%3Adev)
 [![Coverage](https://codecov.io/gh/JuDO-dev/JuDO.jl/branch/dev/graph/badge.svg)](https://codecov.io/gh/JuDO-dev/JuDO.jl)