leaf: Terminal Markdown previewer with a GUI-like experience.

Leaf is an ambitious piece of tooling that solves a persistent friction point in modern developer workflows: the lack of rich, graphical Markdown previewing within the terminal. Unlike simple `markdown` CLI tools that provide raw text output, Leaf aims to be a true editor previewer, offering the structural polish of a dedicated IDE while remaining entirely confined to the CLI. Technically, its implementation is impressive. The inclusion of native LaTeX math rendering—displaying `$x$` and `$$E=mc^2$$` correctly—elevates it beyond a standard Markdown parser. This capability alone positions it as a powerful tool for documentation sites or academic tech blogs. Furthermore, the watch mode (`leaf --watch`) is not merely a simple file tail; it manages state and reloads the preview at a smooth, semi-real-time interval, offering a highly responsive experience that mimics a live development environment. For developers, the combination of advanced features like fuzzy file picking, an active TOC sidebar, and seamless integration with standard input (e.g., piping output from an LLM or another CLI tool) is where Leaf shines. The CLI deep-dive into usage (e.g., `leaf --watch TESTING.md`, or `claude "..." | leaf --watch`) demonstrates a tool designed not just for casual use, but for robust integration into automated, content-generating pipelines. The developer experience, complete with keybindings and advanced pickers, shows meticulous attention to detail. While the feature set is undeniably powerful and the engineering effort is evident, users should be aware that such rich CLI tools often carry dependency weight. The setup instructions (binary downloads, `npm` installs, and `cargo` builds) are detailed but reflect the inherent complexity of building high-fidelity GUI-like applications in a text-only environment. Nonetheless, for any developer or technical content creator who finds themselves constantly toggling between a local editor and a web-based previewer, Leaf represents a significant, necessary improvement to the terminal toolset.