This is a Firefox extension for development. It is currently feature complete for basic usage, but I have plans to improve over time (see below).
Mark any <link> or <style> element with the attribute data-live-reload to indicate that it should reload behind the scenes, without needing a page refresh.
Click the page action (the icon in the URL bar) to enable live reloading, press again to disable.
There are currently lots of extensions out there that do this exact functionality. Currently this extension has no extra functionality (apart from opt-in via HTML attributes). I built this to experiment with Firefox extensions, but I do have plans for unique features in the future.
The main plan is to allow data-live-reload attribute to be added to any element, even the <body> itself. That will allow you to write HTML in your editor and see the page change in front of your eyes. This would be a unique feature, but we'll see if I get the time/motivation.