what is readme fr?

This repository is a reference guide for GitHub Flavored Markdown, written in Chinese. Its purpose is to demonstrate the syntax used to write README files on GitHub, with working examples showing both the code and the rendered result side by side. GitHub Flavored Markdown is an extended version of the standard Markdown format. It adds features that plain Markdown does not have, and is used not just in README files but also in GitHub issues, comments, and wikis. This guide covers all the major formatting options. The guide walks through horizontal lines, six levels of headings, text formatting options like bold, italic, and strikethrough, line breaks, inline code highlighting, block quotes, code blocks with syntax highlighting for languages like Java, JavaScript, C, and Bash, and tables with alignment options. It also covers ordered lists, unordered lists, and checkbox lists, which are particularly useful for tracking task completion in GitHub issues. Beyond standard Markdown, the guide covers embedding images from the web or from within a repository, creating text hyperlinks and image links, using anchor links to jump to sections within the same page, and adding emoji using GitHub shortcode syntax. There is also a section on the diff syntax, which displays added and removed lines in color, and a section on useful HTML tags like collapsible sections and centered content. The repository is primarily a learning reference and demonstration file rather than a software project. All examples are written in Chinese.