title: Prism.js not showing markup
body: <p>I am using the Prism.js plugin. I have a text field where you can type/paste your code, click "Submit," and it will display it in a div below the textarea. I've also included a dropdown where you can pick the language you're using from a list. Everything works great, except that any &lt; > tags do not show up (i.e. html tags, preprocessor directives in C/C++, etc). Does anyone know if I missed a plugin from the download page? 
  I've made it to where instead of specifying a specific language with </p>
  
  <pre><code>&lt;pre&gt;&lt;code class="language-java"&gt;&lt;/code&gt;&lt;/pre&gt;
  </code></pre>
  
  <p>I've made it where the php will append the class name from the dropdown. </p>
  
  <p>Here is my code. As I said, everything is working except those tags: </p>
  
  <p>The HTML:</p>
  
  <pre><code>&lt;select required name="language-select" class="form-control" id="language-selector"&gt;
              &lt;option value="" selected disabled&gt;Language&lt;/option&gt;
              &lt;option value="markup"&gt;Markup&lt;/option&gt;
              &lt;option value="apacheconf"&gt;Apache Conf&lt;/option&gt;
              &lt;option value="aspnet"&gt;ASP.NET&lt;/option&gt;
              &lt;option value="bash"&gt;Bash&lt;/option&gt;
              &lt;option value="c"&gt;C&lt;/option&gt;
              &lt;option value="csharp"&gt;C#&lt;/option&gt;
              &lt;option value="cpp"&gt;C++&lt;/option&gt;
              &lt;option value="css"&gt;CSS&lt;/option&gt;
              &lt;option value="java"&gt;Java&lt;/option&gt;
              &lt;option value="javascript"&gt;JavaScript&lt;/option&gt;
              &lt;option value="matlab"&gt;MatLab&lt;/option&gt;
              &lt;option value="objectivec"&gt;Objective C&lt;/option&gt;
              &lt;option value="perl"&gt;Perl&lt;/option&gt;
              &lt;option value="php"&gt;PHP&lt;/option&gt;
              &lt;option value="powershell"&gt;PowerShell&lt;/option&gt;
              &lt;option value="python"&gt;Python&lt;/option&gt;
              &lt;option value="ruby"&gt;Ruby&lt;/option&gt;
              &lt;option value="scala"&gt;Scala&lt;/option&gt;
              &lt;option value="smalltalk"&gt;Smalltalk&lt;/option&gt;
              &lt;option value="sql"&gt;SQL&lt;/option&gt;
          &lt;/select&gt;
          &lt;br/&gt;
          &lt;button id="drive_submit_btn" class="btn btn-md" type="submit"&gt;Submit&lt;/button&gt;
      &lt;/div&gt;
  &lt;/form&gt;
  &lt;div class="show-code"&gt;
      &lt;script src="custom-js/prism.js"&gt;&lt;/script&gt;
      &lt;!-- Get language selection from dropdown and append it to language class. Echo the text as highlighted code --&gt;
      &lt;pre&gt;&lt;code class="language-&lt;?php echo $language?&gt;"&gt;&lt;?php echo $user_code; ?&gt;&lt;/code&gt;&lt;/pre&gt;
  
  &lt;/div&gt;
  </code></pre>
  
  <p></p>
  
  <p>The relevant PHP:</p>
  
  <pre><code>$user_code = "";
  $language = "";
  if (!empty($_POST["code_input"])) { //get input from textarea and dropdown
  $user_code = $_POST["code_input"];
  $language = $_POST['language-select'];
  </code></pre>
  
  <p>}</p>
  
  <p>Here is a screenshot to show that code works, except for the &lt;> tags:</p>
  
  <p>Before "Submit", I choose the C language:
  <a href="https://i.stack.imgur.com/my29y.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/my29y.png" alt="Choosing Language"></a></p>
  
  <p>And here is after submission. Notice how the #include is missing the &lt;> tags? I don't know how to fix this. Any suggestions? 
  <a href="https://i.stack.imgur.com/KZZwI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KZZwI.png" alt="enter image description here"></a></p>