Fixed search error in the documentation frontend

[jmaruland]

This PR solve a search error in the documentation frontend, where any time a query was requested from the search bar, the website stayed hanging and never showed the results; it showed the searching message indefinitely and the error message in the browser was "Uncaught ReferenceError: jQuery is not defined".

[padraic-shafer]

@jmaruland Confirming that building the docs with your change worked for me locally.

Adding this link for posterity, in case we wonder 2-years later why this configuration setting is present. :-)

[jmaruland]

@padraic-shafer I noticed this issue a couple of weeks ago and I thought at the moment that the problem was with my browser and it's cache probably.
It actually caught my attention last week, when I noticed the same problem with the bluesky documentation. That being said, the same issue is currently present in the bluesky documentation and probably, in other documentation sites under blueskyproject.io.