"where" tab completion

Describe the bug

Complete nuub here, I don't even know how this is supposed to work, please be gentle :)

Imo, the tab comletion for where doesn't work like expected, it completes files instead of key words as shown in https://www.nushell.sh/commands/docs/where.html.

How to reproduce

1. type ls | where

Expected behavior

I'd like to see which key words can be used with where as completion

Screenshots

Configuration

| key                | value                                                            |
| ------------------ | ---------------------------------------------------------------- |
| version            | 0.84.0                                                           |
| branch             | makepkg                                                          |
| commit_hash        | d2abb8603abab43ec4a6d4ed56f9018790b99dce                         |
| build_os           | linux-x86_64                                                     |
| build_target       | x86_64-unknown-linux-gnu                                         |
| rust_version       | rustc 1.71.1 (eb26296b5 2023-08-03) (Arch Linux rust 1:1.71.1-1) |
| cargo_version      | cargo 1.71.1                                                     |
| build_time         | 2023-08-23 02:21:39 +00:00                                       |
| build_rust_channel | release                                                          |
| allocator          | standard                                                         |
| features           | dataframe, default, extra, sqlite, trash, which, zip             |
| installed_plugins  |                                                                  |

Additional context

Thanks for this awesome shell !

Reproduce the issue with ls | where followed by Tab on the reported Nushell version, then trace the where command's tab-completion entry point. Compare the result with the keyword list shown in the linked where documentation; done means keyword suggestions appear instead of file completions.