title: doxygen markdown fails to parse fenced code block
body: <p>Doxygen fails to parse <a href="http://www.doxygen.nl/manual/markdown.html#md_fenced" rel="nofollow noreferrer">fenced code blocks</a> in a markdown file. Here's my snippet:</p>
  
  <pre><code>~~~~~~~~~~~~~~~~~~~~{.cpp}
  #include &lt;cstdio&gt;
  
  int main() {
      printf("Hello World");
  }
  ~~~~~~~~~~~~~~~~~~~~~~~~~~
  </code></pre>
  
  <p>This appears in the output as plaintext.</p>
  
  <blockquote>
  <pre><code>
  int main() { printf("Hello World"); } ~~~~~~~~~~~~~~~~~~~~~~~~~~
  </code></pre>
  </blockquote>
  
  <p>What is my mistake here?</p>