Update README.md

Author: invalidusrname

README.md

@@ -1,6 +1,7 @@
 ![Impressionist Logo](https://github.com/charlotte-ruby/impressionist/raw/master/logo.png)
 
 [![Main](https://github.com/charlotte-ruby/impressionist/actions/workflows/main.yml/badge.svg)](https://github.com/charlotte-ruby/impressionist/actions/workflows/main.yml)
+[![Maintainability](https://qlty.sh/gh/charlotte-ruby/projects/impressionist/maintainability.svg)](https://qlty.sh/gh/charlotte-ruby/projects/impressionist)
 
 WE ARE LOOKING FOR MAINTAINERS.  CONTACT @johnmcaliley IF YOU ARE INTERESTED IN HELPING
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