The "Peek" feature they showed in a tweet seems cool, is there an extension for that in Firefox? Where you can get a tab-within-a-tab to view an article or etc without opening a tab yet. I would definitely install an extension to be able to right-click "Preview Link" or "Preview Tab" or etc. I did a quick search for "Preview Link" and "Peek" and nothing really showed up. There was one "simple link preview" but I tried installing it and it just seems super buggy so I uninstalled.