Remove missing stable docs

Author: MilesCranmer

README.md

@@ -2,7 +2,6 @@
 
 ![logo](https://github.com/SymbolicML/DynamicQuantities.jl/assets/7593028/a278d0c1-2f95-416b-ba04-82750074146b)
 
-[![Stable](https://img.shields.io/badge/docs-stable-blue.svg)](https://symbolicml.org/DynamicQuantities.jl/stable/)
 [![Dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://symbolicml.org/DynamicQuantities.jl/dev/)
 [![Build Status](https://github.com/SymbolicML/DynamicQuantities.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/SymbolicML/DynamicQuantities.jl/actions/workflows/CI.yml?query=branch%3Amain)
 [![Coverage](https://coveralls.io/repos/github/SymbolicML/DynamicQuantities.jl/badge.svg?branch=main)](https://coveralls.io/github/SymbolicML/DynamicQuantities.jl?branch=main)