Keyboard shortcut to focus search bar

[chriskrycho]

A number of sites I use regularly have keyboard shortcuts for focusing the search bar. For example: the Rust std docs and docs.rs both use s to focus the search bar. A few other sites I've seen use / for the same. It would be delightful if Observer did likewise.

I'm happy to submit a PR for it... but I'm rather busy elsewhere in the ecosystem at the moment and it will be a month or two before I get to it. Figured at least writing up the idea might make it easy for someone else to tackle in the meantime.