"main" is the new git default branch

README.md

@@ -12,7 +12,7 @@ command line tools:
 [![Docker](https://img.shields.io/docker/v/kiwix/kiwix-tools?arch=amd64&label=Docker&sort=date)](https://hub.docker.com/r/kiwix/kiwix-tools)
 [![Docker (kiwix-serve)](https://img.shields.io/docker/v/kiwix/kiwix-serve?arch=amd64&label=Docker%20(kiwix-serve)&sort=date)](https://hub.docker.com/r/kiwix/kiwix-serve)
 [![Sandstorm](https://img.shields.io/badge/Sandstorm-kiwix-blue)](https://apps.sandstorm.io/app/5uh349d0kky2zp5whrh2znahn27gwha876xze3864n0fu9e5220h)
-[![Build Status](https://github.com/kiwix/kiwix-tools/workflows/CI/badge.svg?query=branch%3Amaster)](https://github.com/kiwix/kiwix-tools/actions?query=branch%3Amaster)
+[![Build Status](https://github.com/kiwix/kiwix-tools/workflows/CI/badge.svg?query=branch%3Amain)](https://github.com/kiwix/kiwix-tools/actions?query=branch%3Amain)
 [![CodeFactor](https://www.codefactor.io/repository/github/kiwix/kiwix-tools/badge)](https://www.codefactor.io/repository/github/kiwix/kiwix-tools)
 [![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0)