1. First let's create a sample directory:

mkdir try-docs
cd try-docs/

2. Start a new node project and install docs-core and docs-theme-default:

npm init --yes
...
npm i docs-core docs-theme-default --save-dev

3. Create a docsfile.js

module.exports = {
  theme: 'default'
}

4. Create a README.md

<!----
@name Try Docs
@page home
@markdown
---->

# WOOHOO

Trying docs for the first time

5. Start the docs server

docs server

then go to http://localhost:4444

To see more things you can document see docs-plugin-default-annotations

For a more in-depth example see docs-example