Earlier quoted context omitted.
Instead, add !github or !npm to the beginning of the query to use those site's internal searches. For a specific fulltext site search, "site:" works.
But that isn't the point. The point is that in Google you don't need to do that — it just knows what you're searching on (possibly) due to the personalisation.
That is, of course, true. I personally prefer it this way, though. Now I know where I end up by triggering the right mechanics, instead of Google knowing where I end up becase it just keeps track of me that much.
I can live with prepending !gh to my search. Most of the !bangs I use are two or three letters.