Update README.md

Author: Dalmurii

README.md

@@ -1,7 +1,7 @@
 # Ann
 > Rel-v1.0.0
 
-[![ae2f-workflow](https://github.com/ae2f/Ann/actions/workflows/cmake-test.yml/badge.svg)](https://github.com/ae2f/Ann/actions/workflows/cmake-test.yml)
+[![ae2f-workflow](https://github.com/ae2f/Ann/actions/workflows/cmake-test.yml/badge.svg?branch=main)](https://github.com/ae2f/Ann/actions/workflows/cmake-test.yml)
 
 ANN interfaces with basic implementation for example.