add an option to autofill the first completion immediately when called (à la vim)

Basics

• I have done a basic search through the issue tracker to find similar or related issues.
• I have made myself familiar with the available features of Nushell for the particular area this enhancement request touches.

Related problem

First let me state that I love Nushell and it made all shells greyish when I got used to that one !

But ... there's this thing that itched me for ages : when I find the completion that I want, I usually either press Enter to launch the command or Space to jump to another command argument. But in Nushell, pressing Enter just selects the completion, so I always have to double it, and pressing space doesn't end the completion session, so the menu pre-selects the first completion it finds. Sometimes I even press Space, then Enter, which inserts the first match it had found in its second round of completion. Very awkward.

I got used to vim's awesome completion ergonomy and I really wish I could have that in nu. Vim and Neovim have by default wildmode=full, which lets it insert the first completion immediately after I press Tab. I think my zsh config used to behave like that too. I really miss that feature in Nushell, and I find myself constantly pressing Enter. Enter usually is a "commit" button, one presses it when one's done. (That's a point of view on ergonomics, of course, and I understand some would disagree - which is why I'm asking for an option.)

Describe the solution you'd like

After I press Tab, the first selection would be added in the command line (not just selected in the menu). And the completion would be aborted if I pressed Escape (that would mean the command line would get back to where it was before I activated completion). There is no need to press Enter ever. And pressing space ends the completion.

Describe alternatives you've considered

Honestly, I considered getting back to zsh, but that would be painful on other aspects. Nushell is quite addictive :)

Additional context and details

I tried hard to find an issue that asks for the same, but couldn't find any. I just remember someone reported the strange behaviour on Space not ending completion session.