You would have to look at that .sh script file and see what it did for the install. I’m not familiar with that feeder but it looks like a fork of adsbexchange. It has two services. theairtraffic-feed and theairtraffic-mlat. You could stop those services, and disable them so they won’t start at boot.
The uninstall.sh file downloaded by the wget command in my last post, does all the uninstall and cleanup. The wget command downloads the uninstall.sh file from the site from where the app was installed.