title: Select2 start with input field instead of dropdown
body: <p>I use the js library <a href="http://ivaynberg.github.io/select2/" rel="noreferrer">select2</a>. This is a screenshot of what I have now:<br>
  <strong>Start:</strong><br>
  <img src="https://i.stack.imgur.com/HKf2c.png" alt="enter image description here"> <br>
  <strong>Click on dropdown:</strong><br>
  <img src="https://i.stack.imgur.com/AhQ09.png" alt="enter image description here"></p>
  
  <p>Now is it possible to have an input field to start with and not directly a dropdownlist? I know it's possible because you can find it on the select2 site. An example is this: 
  <img src="https://i.stack.imgur.com/CSRs7.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/81xTZ.png" alt="enter image description here"></p>
  
  <p>But the documentation is very brief. This is what I have now:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;input type="text" name="questions[question1]" id="question1" class="question1" style="width:500px"/&gt;
  </code></pre>
  
  <pre class="lang-js prettyprint-override"><code>function createQuestionTags(data, question_number){
    $(".question" + question_number).select2({
      createSearchChoice: function (term, data) {
        if ($(data).filter(function () {
          return this.text.localeCompare(term) === 0;
        }).length === 0) {
          return {
            id: term,
            text: term
          };
        }
      },
      data: data,
      placeholder: "Enter Question",
      allowClear:true
    });
  }
  </code></pre>
  
  <p>(The data is received from an ajax call)</p>