title: Write json to .txt file
body: <p>im serializing a List of string to a Json string and then generating a File from the json string but for some reason my file doesnt have the "{}" of my json.
  This is my List Serialization:</p>
  
  <pre><code>List&lt;string&gt; list = new List&lt;string&gt;();
  
  foreach(item in Model){list.Add(item)}
  
  var reqUsers = list;
  var json = JsonConvert.SerializeObject(reqUsers);
  
  System.IO.File.WriteAllText(@"\path.txt", json);
  </code></pre>
  
  <p>My path.txt show this:</p>
  
  <pre><code>["ENS FRUTAS","REST","CENAS","$26.50",0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,"$26.50"]
  </code></pre>
  
  <p>But i need my output like this:</p>
  
  <pre><code>[["ENS FRUTAS","REST","CENAS","$26.50",0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,"$26.50"]]
  </code></pre>
  
  <p>My foreach loop to fil my list:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code> for (int i = 1; i &lt;= 31; i++)
                          {
                          var value = 0;
                           if (item.Fecha.Day == i) { value = item.Cantidad; costo = costo + item.Total; }
                                                      total += value;
                           }
                                                     list.Add(item.Descripcion);
                                                     list.Add(item.Pdv);
                                                     list.Add(item.Rid);
                                                     list.Add(((costo / (total + 1)).ToString("C")));
                                                      for (int i = 1; i &lt;= 31; i++)
                                                      {
                                                          var value = 0;
                                                          list.Add(value.ToString());
                                                          int month = item.Fecha.Month;
                                                          if (item.Fecha.Day == i) { value = item.Cantidad; list.Add(value.ToString()); }
                                                         
                                                      }
                   list.Add(total.ToString());
                   list.Add((((costo / (total + 1)) * total).ToString("C")));
                          }</code></pre>
  </div>
  </div>
  </p>
  
  <p>i want each time my list finish a serie of the foreach loop to make the data enclosed by []
  How can i do this? </p>