docs: clarify TUI and CLI terminology in README (#51)

## Description

This PR updates the README documentation to clarify the distinction
between the TUI (Terminal User Interface) and CLI modes of the tool. The
changes make it clearer that the tool serves two purposes: an
interactive TUI mode for visual interaction and a traditional CLI mode
for scripting and automation.

## Type of Change

- [x] Documentation update

## Changes Made

- Updated tagline to describe the tool as "TUI + CLI" instead of just
"CLI"
- Clarified that interactive mode is a "TUI" (Terminal User Interface)
- Reorganized Usage section to clearly distinguish between TUI and CLI
modes
- Added explicit examples showing TUI mode vs CLI mode usage
- Updated feature list to highlight both TUI and CLI capabilities
- Improved clarity throughout by using precise terminology

## Testing

- [x] Documentation changes reviewed for clarity and accuracy
- [x] Build passes
- [x] All 192 tests pass

## Checklist

- [x] My code follows the code style of this project
- [x] I have performed a self-review of my own code
- [x] I have updated the documentation accordingly
- [x] My changes generate no new warnings
- [x] New and existing unit tests pass locally with my changes

Author: dines-rl

README.md

@@ -4,7 +4,7 @@
 [![CI](https://github.com/runloopai/rl-cli/actions/workflows/ci.yml/badge.svg)](https://github.com/runloopai/rl-cli/actions/workflows/ci.yml)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
 
-An interactive CLI for interacting with the [Runloop.ai](https://runloop.ai) platform. Use it as an **interactive command-line application** with rich UI components, or as a **traditional CLI** for scripting and automation.
+A **TUI + CLI** for the [Runloop.ai](https://runloop.ai) platform. Use it as an **interactive TUI** (Terminal User Interface) with rich UI components, or as a **traditional CLI** for scripting and automation.
 
 📖 **[Full Documentation](https://docs.runloop.ai/docs/tools/cli)**
 
@@ -15,10 +15,10 @@ An interactive CLI for interacting with the [Runloop.ai](https://runloop.ai) pla
 ## Quick Example
 
 ```bash
-# Interactive mode - launches a beautiful UI menu
+# TUI mode - launches an interactive terminal UI
 rli
 
-# Traditional CLI mode - perfect for scripts
+# CLI mode - perfect for scripts and automation
 rli devbox list                    # Outputs JSON/text
 rli devbox create --name my-devbox
 rli devbox exec <devbox-id> echo "Hello World"
@@ -27,10 +27,11 @@ rli devbox delete <devbox-id>
 
 ## Features
 
+- 🖥️ **TUI mode** — Interactive terminal UI with menus, tables, and real-time updates
+- 🎯 **CLI mode** — Traditional commands with text, JSON, and YAML output for scripting
 - ⚡ Fast and responsive with pagination
 - 📦 Manage devboxes, snapshots, and blueprints
-- 🚀 Execute commands, ssh, view logs in devboxes
-- 🎯 Traditional CLI with text, json, and yaml output modes.
+- 🚀 Execute commands, SSH, view logs in devboxes
 - 🤖 **Model Context Protocol (MCP) server for AI integration**
 
 ## Installation
@@ -53,13 +54,23 @@ Get your API key from [https://runloop.ai/settings](https://runloop.ai/settings)
 
 ## Usage
 
-### Interactive CLI
+### TUI (Interactive Mode)
 
 ```bash
-rli                    # Run the interactive console
+rli                    # Launch the interactive TUI
 rli --help             # See help information
 ```
 
+### CLI (Scripting Mode)
+
+All commands support `--output` (`-o`) for format control:
+
+```bash
+rli devbox list                      # Default text output
+rli devbox list -o json              # JSON output
+rli devbox list -o yaml              # YAML output
+```
+
 ## Command Structure
 
 The CLI is organized into command buckets:
@@ -160,7 +171,7 @@ rli mcp start --http --port 8080
 
 ## Theme Configuration
 
-The CLI supports both light and dark terminal themes and will automatically select the appropriate theme.
+The TUI supports both light and dark terminal themes and will automatically select the appropriate theme.
 
 ## Development