Scripts for cjs (a chrome plugin to inject your js)
Install extension "Custom JavaScript for Websites 2" (cjs) in your Chrome based Browser (https://chrome.google.com/webstore/detail/custom-javascript-for-web/ddbjnfjiigjmcpcpkmhogomapikjbjdk).
Access site, click on cjs extension button and add the script
You can add as external script copying the permalink or copy-pasting the script code.