add tests for algolia search

[Kent55]

Might be worth adding some tests for the algolia search. The latest update implements a popup rather than dropdown and supports the hotkey combination ctrl+k. Would be good to add a test to very this opens both in response to the hotkey and also from a user click event. It would also be worthwhile testing that the searching functionality returns results and that they are correct and also that it doesn't return results when incorrect.

Currently, algolia indexes the site every 24 hours to index any new or updated docs articles.