dsh-docs-panel: Embed local Markdown documents in the DSH sidebar

dsh-docs-panel is an MIT-licensed DSH Web plugin developed by mlosun, designed to integrate local Markdown documents into the DSH sidebar to solve the hassle of frequently switching editors to view notes. Since v0.1.0, it runs as an independent tab within dsh-better-sidebar (≥v0.4.0). It automatically scans .md files in a specified directory (defaulting to ~/.dsh/docs, which is customizable and permanently saved) and displays them in a well-formatted web page within the sidebar. It supports light/dark theme adaptation, rendering of headings/tables/code blocks, outline smooth scrolling, and one-click code copying. Additionally, it provides "Chrome Open" and "VS Code Open" buttons, though it currently only supports macOS. To install, you must first add the dependency dsh-