expo: provide options to modifiy directional selection keys when entering the overview

[A7R7]

Currently you can use hjkl and ↑↓←→ to move around in the expo overview. But this behavior is hard coded. Although this suit most of the time, but some people may not like the default keybindings, for example they may hope to remap them to wasd or ijkl, or even jkl; like me. Therefore it may be better to provide options for users to remap those keybindings.

[A7R7]

I may try to implement this but I'm a little busy right now

[ammen99]

A late response, but nonetheless: PRs welcome.

[pamo22]

I am working on this, do we want to keep the hard-coded behavior for enter and escape?

[A7R7]

Thank you! I think it may be better to keep enter and the escape the default value but make them configurable.