docs: Big reorganize (#45276)

Release Notes:

- N/A 

Overview

Restructures the documentation navigation to be organized by user goals
rather than feature lists. Introduces a new "Working with Code" section
and reorganizes existing content into clearer groupings.

### Navigation Changes

**New top-level sections:**
- **Working with Code** — Groups editing, navigation, and execution
features by workflow
- **Reference** — Dedicated section for lookup-only content (settings,
actions, CLI)
- **Coming From...** — Migration guides grouped together

**Reorganized sections:**
- **Customization** — Renamed from "Configuration," focused on
appearance and keybindings
- **Account & Privacy** — Consolidated auth, privacy, and telemetry
pages

New Files

| File | Purpose |
|------|---------|
| `editing-code.md` | Overview page for editing features |
| `finding-navigating.md` | Overview page for navigation tools with
quick reference |
| `running-testing.md` | Overview page for tasks, debugger, and REPL |
| `reference/all-settings.md` | Settings reference (moved/renamed) |
| `reference/cli.md` | CLI reference (moved) |

### Content Moves

| Page | From | To |
|------|------|-----|
| Snippets | Customization | Working with Code → Editing Code |
| Code Completions | (flat) | Working with Code → Editing Code |
| Diagnostics | (flat) | Working with Code → Editing Code |
| Multibuffers | (flat) | Working with Code → Editing Code |
| Command Palette | (flat) | Working with Code → Finding & Navigating |
| Outline Panel | (flat) | Working with Code → Finding & Navigating |
| Tab Switcher | (flat) | Working with Code → Finding & Navigating |
| Tasks | (flat) | Working with Code → Running & Testing |
| Debugger | (flat) | Working with Code → Running & Testing |
| REPL | (flat) | Working with Code → Running & Testing |
| All Settings | Configuration | Reference |
| CLI | (various) | Reference

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>
Co-authored-by: Zed Zippy <234243425+zed-zippy[bot]@users.noreply.github.com>

docs/src/languages/diff.md

@@ -6,7 +6,7 @@ Diff support is available natively in Zed.
 
 ## Configuration
 
-Zed will not attempt to format diff files and has [`remove_trailing_whitespace_on_save`](https://zed.dev/docs/configuring-zed#remove-trailing-whitespace-on-save) and [`ensure-final-newline-on-save`](https://zed.dev/docs/configuring-zed#ensure-final-newline-on-save) set to false.
+Zed will not attempt to format diff files and has [`remove_trailing_whitespace_on_save`](https://zed.dev/docs/reference/all-settings#remove-trailing-whitespace-on-save) and [`ensure-final-newline-on-save`](https://zed.dev/docs/reference/all-settings#ensure-final-newline-on-save) set to false.
 
 Zed will automatically recognize files with `patch` and `diff` extensions as Diff files. To recognize other extensions, add them to `file_types` in your Zed settings.json: