title: Highlight with Searchkick and Elasticsearch
body: <p>I installed Searchkick and Elasticsearch for the first time. </p>
  
  <p>I have the basics working and am trying to include the <a href="https://github.com/ankane/searchkick#highlight" rel="nofollow">highlight</a> feature. </p>
  
  <p><strong>The Index:</strong> </p>
  
  <pre><code>    &lt;%= form_tag books_path, method: :get do %&gt;
        &lt;%= text_field_tag :q, nil %&gt;
      &lt;% end %&gt;
      &lt;div class="row"&gt;
        &lt;div class="col-md-8"&gt;
          &lt;% @books.each do |book| %&gt;
            &lt;div class="media"&gt;
              &lt;div class="media-body"&gt;
                &lt;h4 class="media-heading"&gt;
                  &lt;%= link_to book.title, book %&gt;
                &lt;/h4&gt;
                &lt;small&gt;
                  &lt;%= book.description %&gt;
                &lt;/small&gt;&lt;/br&gt;
                &lt;% if policy(book).edit? %&gt; 
                  &lt;%= link_to 'Edit', edit_book_path(book) %&gt;
                  &lt;% end %&gt;
              &lt;/div&gt;
            &lt;/div&gt;
          &lt;% end %&gt;
          &lt;%= paginate @books %&gt;
        &lt;/div&gt;
        &lt;div class="col-md-4"&gt;
          &lt;% if policy(Book.new).create? %&gt;
          &lt;%= link_to "New Book", new_book_path, class: 'btn btn-success' %&gt;
          &lt;% end %&gt;
        &lt;/div&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p><strong>Controller</strong></p>
  
  <pre><code>        def index
            query = params[:q].presence || "*"
            @books = Book.search(query, field: [:title], highlight: {tag: "&lt;strong&gt;"})
            authorize @books
          end
  </code></pre>
  
  <p><strong>Model</strong></p>
  
  <pre><code>    class Book &lt; ActiveRecord::Base
        require 'elasticsearch/model'
        searchkick highlight: [:title, :description]
  </code></pre>
  
  <p>What am I missing? </p>