Add Chinese README and improve documentation clarity with bilingual support

[Copilot]

This PR implements comprehensive bilingual documentation support as requested in the issue, based on the forge-1.20.1 branch.

🌟 What's Changed

✅ Enhanced English README

• Improved clarity and flow: Restructured content with better organization and more intuitive descriptions
• Visual enhancements: Added emojis and improved formatting for better readability
• Detailed feature explanations: Expanded descriptions based on actual mod functionality including particle effects, sound feedback, and safety checks
• Better usage instructions: Clear examples and organized sections for easier understanding

✅ Complete Chinese Translation

• New file: Added README_zh.md with full Chinese translation
• Proper terminology: Used appropriate Chinese terms for the Minecraft community
• Consistent structure: Maintains the same visual appeal and organization as the English version
• Cultural adaptation: Adapted content to be more natural for Chinese readers

✅ Bilingual Navigation System

• Language switching: Added navigation links at the top of both README files
• Seamless experience: Users can easily switch between [English](README.md) and [中文](README_zh.md)
• Consistent implementation: Both files include the same navigation pattern

📋 Key Improvements

Before:

# OnlyTP

A Minecraft Forge mod that provides enhanced teleportation functionality. Easily teleport to your friends to help them.

## Features
- **Simple Commands**: Easy-to-use commands for teleporting players
- **No Dependencies**: This mod does not require any additional libraries or mods to function

After:

# OnlyTP

[English](README.md) | [中文](README_zh.md)

OnlyTP is a lightweight Minecraft Forge mod that enhances your gameplay with convenient teleportation features. Whether you're exploring vast worlds or helping friends in need, OnlyTP makes traveling across your Minecraft server simple and efficient.

## ✨ Features
- **🎯 Simple Commands**: Intuitive teleportation with easy-to-remember commands
- **🌟 Enhanced Experience**: Teleport with elegant particle effects and sound feedback
- **🔐 Smart Safety Checks**: Prevents teleporting to offline, dead, or disconnected players
- **⚡ Zero Dependencies**: No additional mods or libraries required - just install and play
- **🌐 Multiplayer Ready**: Perfect for collaborative gameplay and server environments

🔧 Technical Details

• ✅ Based on forge-1.20.1 branch as requested
• ✅ Build verification passed - no regressions introduced
• ✅ Maintains all existing functionality while improving documentation
• ✅ Follows GitHub markdown best practices for both languages

🌍 Community Impact

This change makes the OnlyTP mod accessible to both English and Chinese-speaking Minecraft communities, with improved documentation that's easier to understand and more visually appealing for all users.

Fixes the requirements outlined in the original issue for bilingual README support and improved documentation clarity.

---

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.