Update README.md

Co-authored-by: Tim Meusel <tim@bastelfreak.de>

README.md

@@ -2,7 +2,7 @@
 
 [![CI](https://github.com/voxpupuli/puppet-swap_file/actions/workflows/ci.yml/badge.svg)](https://github.com/voxpupuli/puppet-swap_file/actions/workflows/ci.yml)
 [![License](https://img.shields.io/github/license/voxpupuli/puppet-swap_file.svg)](https://github.com/voxpupuli/puppet-swap_file/blob/master/LICENSE)
-[![puppetmodule.info docs](https://www.puppetmodule.info/images/badge.png)](https://www.puppetmodule.info/m/puppet-swap_file)
+[![puppetmodule.info docs](https://www.puppetmodule.info/images/badge.svg)](https://www.puppetmodule.info/m/puppet-swap_file)
 [![Donated by petems](https://img.shields.io/badge/donated%20by-petems-fb7047.svg)](#transfer-notice)
 
 [![Puppet Forge Endorsement](https://img.shields.io/puppetforge/e/puppet/swap_file.svg)](https://forge.puppetlabs.com/puppet/swap_file)