Search engine management - add and remove search engines

[Tannim]

It will be cool if you can add and remove search engines in Firefox, just like in Vivaldi.

I don't think it's hard to do.

[fasseg]

I don't want to install an add-on just to use another custom search engine. I'd very much like the option to add a custom search engine like librex using just a URL and a query param. Just look at the mobile firefox version. It works perfectly nice there.