xby-rfc-doc: DeepSeek Harness RFC Documentation Service Plugin

`xby-rfc-doc` is a DeepSeek Harness (DSH) plugin maintained by `xby-skill`, essentially an MCP server. It addresses the hassle of agents accessing Internet standards documents, which are cumbersome to retrieve and difficult to control programmatically. The plugin provides core features for setting an API key and fetching the full text of RFC documents or specific sections by number or keyword. After registering on the official website to obtain a key and installing the plugin, users can programmatically interact with RFC documents in DSH.