Instruct testers that they may need to press fn with function keys

[jscholes]

In a lot of "read information about..." tests, we instruct macOS testers to press VO+F3 and VO+F4. But with the default configuration on my MacBook Air at least, these commands only work when fn is held down as well.

I don't think it's at all appropriate to add fn to the key combinations themselves, as users may've changed the configuration and we would just end up creating the same problem in reverse. But maybe there could be some sort of flag attached to function keys which trigger a note in the testing UI? Alternatively, it may just be a reasonable assumption that testers are experienced enough to know this, and if not they shouldn't be running the tests?