title: How does sonarQube calculate technical debt
body: <p>In the new version of sonarqube, the documntation states that technical debt (TD)</p>
  
  <pre><code>TD= Effort to fix all maintainability issues. The measure is stored in minutes in the DB. An 8-hour day is assumed when values are shown in days.
  </code></pre>
  
  <p>However, how does sonarqube measure maintainability issues?</p>