Update readme.md

Author: sdebacker

readme.md

@@ -1,6 +1,7 @@
 # Form
 
 [![tests](https://github.com/typicms/form/actions/workflows/tests.yml/badge.svg?branch=main)](https://github.com/typicms/form/actions/workflows/tests.yml)
+[![Coverage Status](https://coveralls.io/repos/github/typicms/form/badge.svg?branch=main)](https://coveralls.io/github/typicms/form?branch=main)
 [![Rector](https://github.com/typicms/form/actions/workflows/rector.yml/badge.svg?branch=main)](https://github.com/typicms/form/actions/workflows/rector.yml)
 [![Pint](https://github.com/typicms/form/actions/workflows/pint.yml/badge.svg?branch=main)](https://github.com/typicms/form/actions/workflows/pint.yml)