dsh-anydoc-markdown: DeepSeek Harness Document-to-Markdown and Image Description Plugin

`dsh-anydoc-markdown` is a plugin for DeepSeek Harness designed to address the challenge of agents understanding images in non-text files (such as Word and PDF documents). The plugin converts documents into GitHub-style Markdown, uses VLM to describe images and replace them with placeholders, and supports drag-and-drop upload, batch requests, and offline mode. It provides a `convert_document` tool for agents to invoke on demand, with results either returned inline or saved to a local directory.