Note everyone has the luxury of two screens or a computer and a tablet so if you are wanting to use a website reference while you are playing games on Steam then you might be resorting to using print outs or a smartphone. These are not the most convenient solutions by any means!
If you don’t already know, Steam actually includes a browser which you can access whilst in-game by pressing Shift+Tab on the keyboard and click on Browser at the bottom for the screen. A new browser window should pop up and you should be up and running just like any other regular browser.
I find this very handy when playing TF2 and wanting to reference custom blueprints for weapons crafting.