Did you even look at the article?
The concept of Google must be above and beyond both Aunt Sally, Cousin Joe, and quite possibly, yourself.
I simply added a performance tip and your all up in arms about the documentation for it. Start reading and perhaps your find what your looking for.
If you insist on knowing how I found out about "about:config", I was annoyed at web address bar and the search results that it was displaying when I typed an address in. I simply Googled it and wouldn't you believe it! I found a story telling me how to shut off the "browser.urlbar.maxRichResults". It's set to 12 by default. I simply set mine to -1 and it's gone. THAT is how I found out about it.
Aunt Sally, I don't think would ever know or care about it. But, if I said so for her to run it, that would be because she asked me what I run for a browser and I told her it was Firefox and she wanted to run the same thing. As for Cousin Joe, he'd probably start by looking for it. It's not that difficult really.