Update coverage badge in README [skip ci]

Author: finitearth

README.md

@@ -1,6 +1,6 @@
 ![promptolution](https://github.com/user-attachments/assets/84c050bd-61a1-4f2e-bc4e-874d9b4a69af)
 
-![Coverage](https://img.shields.io/badge/Coverage-90%25-brightgreen)
+![Coverage](https://img.shields.io/badge/Coverage-91%25-brightgreen)
 [![CI](https://github.com/finitearth/promptolution/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/finitearth/promptolution/actions/workflows/ci.yml)
 [![Docs](https://github.com/finitearth/promptolution/actions/workflows/docs.yml/badge.svg?branch=main)](https://github.com/finitearth/promptolution/actions/workflows/docs.yml)
 ![Code Style](https://img.shields.io/badge/Code%20Style-black-black)