I was not able to get this to work on my setup. I added a keyword 'uniquekeyword' to the hackaday bookmark, but if I start typing uni... it just tries to give me a web search. I tried enabling/disabling the search bar and messing with my address bar preferences but no dice.
Counter-intuitively, it does sort of work if I put the keyword as a tag. It still tries to offer me a search as the top hit, but the tag result is the second hit.