Feature Vision Discussion: Completions/Hints

This issue is part of the larger vision discussion managed in #63 to brainstorm and prioritize ideas around features that would make reedline as a line editor for you both viable as well as pleasant to use. Feel free to up-vote features you depend on in other tools/shells as well as suggest new ideas!

Completions Features

• Ability to works as expected or better
  • File and folder completion
    • zsh-style partial path expansion
  • Environment variable completion $nu.env.A<tab>
  • Table column completion (ls).n<tab>
  • Sub-Command completion str <tab>
  • Other
• Ability to add external completions for things like git
• Ability to make completions extensible

Hinting Features

• Ability to change the color of the hints
• Ability to create hints from history
• Ability to have plugable hints specific to a vertical
  • Nushell
  • Azure
  • Dataframe/Polars/DataScience
  • Maths
  • Other
• Ability to complete hints with keybinding
• Ability to change location of hints
  • On prompt line
  • Under prompt line
  • On status bar at the top
  • On staus bar at the bottom

Start with the larger vision discussion in #63, then review the unchecked completion and hinting ideas listed here. No implementation files, tests, or single target are identified; work would first require choosing one capability and defining what completion looks like.