Feishu Create Doc

This creates Feishu (Lark) docs from Markdown with some serious formatting power. You get the usual suspects like headers and lists, but also callouts with emoji, multi column layouts, and automatic Mermaid/PlantUML rendering into visual boards. The syntax is a custom Lark flavored Markdown with XML tags for the fancy stuff. You can drop docs into folders, wikis, or knowledge spaces by passing tokens from the URL. One catch: it wants clean structured content and will choke on really long documents, so they recommend using the append mode from update-doc to build incrementally. The image and file handling is URL only, no direct token uploads.