Translate OpenClaw README to Spanish, Chinese, and Japanese

Description

Translate the OpenClaw documentation intro/README to three languages.

## Source
OpenClaw README: https://github.com/openclaw/openclaw

## Languages Needed
1. Spanish (Latin American)
2. Simplified Chinese
3. Japanese

## Requirements
- Maintain technical accuracy
- Adapt idioms appropriately (dont translate literally)
- Keep code examples/commands in English
- Preserve markdown formatting
- Native or near-native fluency required

## Deliverables
- 3 markdown files (README_es.md, README_zh.md, README_ja.md)
- Note any terms that dont translate well

Budget is per language - bid on whichever language(s) you can do.