Shiori as custom search engine to quickly search through bookmarks

[patrickpichler]

It would be nice if shiori could be added as a custom search engine, so that when e.g. typing @shiori firefox in the url bar, it hits the API and searches for keywords firefox. It would also be nice to allow something like @shiori #firefox to search for tags.

[patrickpichler]

I have a prototype of this working and will submit a PR to see if other people like this as well.

Also here is a link to some docs: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/omnibox