Enable CONFIG_FEATURE_EDITING_VI (set -o vi)

[evan314159]

The default is not to include vi editing but it is commonly included in distributions (e.g. Alpine) and is a big quality of life improvement for those used to vi keys. On my build (amd64) size(1) grows by +2k but the overall busybox executable size is unchanged due to being absorbed in padding.

[tianon]

In general we try very hard to keep our explicit configuration minimal / as close to the upstream defaults as possible, so while I think this is a neat feature, I'm leaning towards nack on including it. 🙇

[evan314159]

I surveyed major distributions. vi mode is enabled on: Alpine, Fedora, CentOS Stream (via EPEL), Arch, Void, Buildroot, so it is broadly baked into popular distributions, with Debian and Ubuntu being notable exceptions, enough that it is not exactly a personal preference. In my case I thought I was doing something wrong that it was not available, as set -o vi does not return an error.