docs: show the correct branch in the build badge

Author: aymanbagabas

README.md

@@ -9,7 +9,7 @@
     <br>
     <a href="https://github.com/charmbracelet/bubbletea/releases"><img src="https://img.shields.io/github/release/charmbracelet/bubbletea.svg" alt="Latest Release"></a>
     <a href="https://pkg.go.dev/github.com/charmbracelet/bubbletea?tab=doc"><img src="https://godoc.org/github.com/charmbracelet/bubbletea?status.svg" alt="GoDoc"></a>
-    <a href="https://github.com/charmbracelet/bubbletea/actions"><img src="https://github.com/charmbracelet/bubbletea/actions/workflows/build.yml/badge.svg" alt="Build Status"></a>
+    <a href="https://github.com/charmbracelet/bubbletea/actions"><img src="https://github.com/charmbracelet/bubbletea/actions/workflows/build.yml/badge.svg?branch=main" alt="Build Status"></a>
 </p>
 
 The fun, functional and stateful way to build terminal apps. A Go framework