Update feature_advanced_keycodes.md (#3672)

Update feature_advanced_keycodes.md (#3672)

* Update feature_advanced_keycodes.md

Probably a better way to word it, but I've solved this issue on reddit several times, had to solve this for friends, ect. It's something worth being in the docs as it's a common issue, and not always intuitive. I have offered this change as I was told by several people "It was never mentioned in the docs".

* Update feature_advanced_keycodes.md

Clear up what was meant to be said.