title: how to set multiple lines in a doxygen paragraph?
body: <p>The following doyxygen comments:</p>
  
  <pre><code>/// @par title
  /// content1
  /// content2
  ///
  </code></pre>
  
  <p>will merge "content1" and "content2" into a single line as follows:</p>
  
  <pre><code>**title**
    content1 content2
  </code></pre>
  
  <p>But how to set multiple lines in a doxygen paragraph, i.e.</p>
  
  <pre><code>**title**
    content1
    content2
  </code></pre>