npm install
npm run build

Please check the index.js file which exports few useful functions:

module.exports = {
  generateOutputWebpage,
  generatePagesFromMarkdownFiles,
  cleanUpFiles,
  buildSitemap,
  md,
};

• generateOutputWebpage is used for generating HTML file from a template HTML string.
• generatePagesFromMarkdownFiles is used for generating HTML files from multiple markdown files.
• cleanUpFiles is used for removing all *.html from a directory.
• buildSitemap is used for building the sitemap.xml for the website.

Also, you could take kframework/k as a reference for building a website using k-web-theme.