refactor: codacys feedback

Author: mfranzke

CODE_OF_CONDUCT.md renamed to CODE-OF-CONDUCT.md

@@ -16,7 +16,7 @@
 [![Join the chat at https://gitter.im/loading-attribute-polyfill/community](https://badges.gitter.im/loading-attribute-polyfill/community.svg)](https://gitter.im/loading-attribute-polyfill/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square)](http://makeapullrequest.com)
 [![Open Source Love](https://badges.frapsoft.com/os/v3/open-source.svg?v=103)](https://github.com/ellerbrock/open-source-badges/)
-[![Contributor Covenant](https://img.shields.io/badge/Contributor%20Covenant-2.0-4baaaa.svg)](CODE_OF_CONDUCT.md)
+[![Contributor Covenant](https://img.shields.io/badge/Contributor%20Covenant-2.0-4baaaa.svg)](CODE-OF-CONDUCT.md)
 
 Fast and lightweight vanilla JavaScript polyfill for native lazy loading, meaning the behaviour to load elements right before they enter the viewport. Provides graceful degradation, and is - not just thatfor - SEO friendly. Handles images with `srcset` and within `picture`, as well as `iframe` elements. `loading="lazy"` will be a huge improvement for todays web performance challenges, so use and polyfill it today!