https://www.avkuzmin.ru/2013/11/%d0%bd%d0%b0%d1%81%d1%82%d1%80%d0%b0%d0%b8%d0%b2%d0%b0%d0%b5%d0%bc-inoreader-%d0%ba%d0%b0%d0%ba-%d0%be%d0%b1%d1%80%d0%b0%d0%b1%d0%be%d1%82%d1%87%d0%b8%d0%ba-rss-%d0%b2-firefox.html
Настраиваем InoReader как обработчик RSS в Firefox