Hello world

This is a test post. It checks how Hashnode renders a Mermaid diagram, a code block and headings on the free plan. It will be replaced by real writing.

A diagram

flowchart LR
  A[Draft in the repo] --> B[Paste into Hashnode]
  B --> C[Published post]

A code block

def greet(name: str) -> str:
    return f"Hello, {name}"

A smaller heading

That is the whole test.