A README is the first document anyone reads when they meet your project. Laying out what the project does and how to install and run it with a clear heading structure makes it far easier to understand.
The basic skeleton is to split sections with headings (#), wrap install commands in code blocks, and organize the feature list with bullets. Adding badges and screenshot images raises both trust and readability.
Use tables to organize options or environment variables, and a checklist to show your roadmap, and the document looks much more structured. All of this is possible with Markdown alone.
Paste your README into AG MD and convert it to HTML to preview how it will look on the actual web.