Public render function of the reading time plugin with overwritable template

reading-time-public-functions.php

<?php

function reading_time_render($post_id){
  // https://medium.com/write-better-wordpress-code/do-not-use-post-meta-fec12a7661
  $db = new  \PublicFunctionOrg\WordPress\ReadingTime\Database();
  $reading_time = $db->get($postId);
  if(!$reading_time) return;
  
  // https://medium.com/write-better-wordpress-code/provide-overwritable-templates-from-your-plugin-c5205f8a3138
  $templates = new \PublicFunctionOrg\WordPress\Templates();
  include $templates->get_template_path("reading-time-template.php");
}

function reading_time_get_content($post_id){
  ob_start();
  // https://gist.github.com/EdwardBock/fa659b67bcf4f568289d0c49c175f42b
  reading_time_render($postId);
  $content = ob_get_contents();
  ob_end_clean();
  return $content;
}

reading-time-template.php

<?php
/**
 * @var int $reading_time
 */
echo "<p>Estimated reading time: $reading_time minutes</p>";