To build upon my earlier post, Integrate Alfred and Dash: Dash supports find-in-page search via a whitespace. To search on a docs page, add a space after the function or keyword name, and then enter your search query.
Array.prototype.unshift() and search on that docs page for the ‘specification’ header, where the associated ECMAScript standards for
unshift are found.
This command from Alfred could look like:
dash unshift specification