Improve visibility and wording around close panel on toggle setting (#63548)

# Objective

- Improve documentation for `close_panel_on_toggle` setting. 

## Solution

- Previous docs were a bit ambiguous and since refactoring the setting
name is not possible at the time, I improved the documentation.

## Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed's UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [ ] Tests cover the new/changed behavior
- [ ] Performance impact has been considered and is acceptable

Release Notes:

- Added the`close_panel_on_toggle` setting to the settings UI and
improved its documentation.

docs/src/reference/all-settings.md

@@ -502,6 +502,16 @@ When enabled, this setting will automatically close tabs for files that have bee
 
 > Note: Dirty files (files with unsaved changes) will not be automatically closed even when this setting is enabled, ensuring you don't lose unsaved work.
 
+## Close Panel on Toggle
+
+- Description: Whether invoking a panel's `ToggleFocus` action while the panel is already focused closes the panel, instead of just moving focus back to the editor. This only applies to a panel's focus-toggle action, not to its regular visibility-toggle action.
+- Setting: `close_panel_on_toggle`
+- Default: `false`
+
+**Options**
+
+`boolean` values
+
 ## Code Lens
 
 - Description: Whether and how to display code lenses from language servers. Code lenses show contextual information such as reference counts, implementations, and other metadata provided by the language server.