Add documentation for Plans and UI options

[yippie]

Most of this is not my work but I really could use the documentation so bumping this.

Added the ui_options list with options that I could find while reviewing source code.

[davidmreed]

@jstvz I don't know all the context around the code changes here, which I think came from your work on the plan commands. Should we take this PR forward or carve off just the doc changes? We have a WI on the backlog to get the source doc that became plan.md published.

[jstvz]

Thank you for your work on this PR. You point out an important documentation gap we need to close.

I'm closing this PR. These changes you've proposed come from a terminal documentation proof of concept that isn't on our roadmap. We acknowledge the need for improved documentation and plan to address these gaps in upcoming releases.