examples.ejs

<%
const postsByCategory = {};
const basicConfigPosts = [];
items.forEach(item => {
  if (item.category === "Basic configuration") {
    basicConfigPosts.push(item)
  } else {
    if (!postsByCategory[item.category]) {
      postsByCategory[item.category] = [];
    }
    postsByCategory[item.category].push(item);
  }
});

// Basic config first
if (basicConfigPosts.length > 0) { %>
<h2>Basic configuration</h2>
<ul>
  <% basicConfigPosts.forEach(post => { %>
    <li>
    <a href="<%= post.path %>"><%=post.title %></a>
    </li> 
  <% }) %> 
</ul>
<% } %>

<% for (const [category, categoryPosts] of Object.entries(postsByCategory)) { %>
  <h2><%= category %></h2>
  <ul>
    <% categoryPosts.forEach(post => { %>
      <li>
        <a href="<%= post.path %>"><%= post.title %></a>
      </li>
    <% }) %>
  </ul>
<% } %>