feat: add plugin rankgpt by ki3dn

[ki3nd]

Plugin Submission Form

1. Metadata

• Plugin Author: ki3dn
• Plugin Name: rankgpt-dify-plugin
• Repository URL: https://github.com/ki3nd/rankgpt-dify-plugin.git

2. Submission Type

• New plugin submission
• Version update for existing plugin

3. Description

This plugin provides an OpenAI-based RankGPT reranker for Dify, reordering retrieved documents by query relevance with configurable sliding-window settings for better performance on larger document lists.

4. Checklist

• I have read and followed the Publish to Dify Marketplace guidelines
• I have read and comply with the Plugin Developer Agreement
• I confirm my plugin works properly on both Dify Community Edition and Cloud Version
• I confirm my plugin has been thoroughly tested for completeness and functionality
• My plugin brings new value to Dify

5. Documentation Checklist

Please confirm that your plugin README includes all necessary information:

• Step-by-step setup instructions
• Detailed usage instructions
• All required APIs and credentials are clearly listed
• Connection requirements and configuration details
• Link to the repository for the plugin source code

6. Privacy Protection Information

Based on Dify Plugin Privacy Protection Guidelines:

Data Collection

Privacy Policy

• I confirm that I have prepared and included a privacy policy in my plugin package based on the Plugin Privacy Protection Guidelines