title: How to Implement Autocomplete for Association in simple_form in Rails 6
body: <p>I'm currently building a book handling project in Rails 6. There are two models <code>Book</code> and <code>Categories</code>, Category can contain many books but a book can only belong to a single category. I'm currently using <code>simple_form</code> <code>f.association</code> to make the form association which creates a dropdown menu of Categories. </p>
  
  <p><code>new.html.erb</code> in Book</p>
  
  <pre><code>    &lt;section class="mt-8"&gt;
      &lt;%= simple_form_for @book, defaults: { input_html: {class: 'form-input mt-1'}, wrapper_html: {class: 'flex flex-col my-2'}} do |f| %&gt;
      &lt;%= f.input :title %&gt;
      &lt;%= f.input :description, input_html: {class: 'form-textarea'} %&gt;
      &lt;%= f.input :amazon_url %&gt;
      &lt;%= f.association :category, collection: Category.all.order(name: :asc),input_html: {class: 'form-select'} %&gt;
      &lt;%= f.button :submit, 'Create New Book', class: 'mt-4 p-2 rounded-md bg-gray-400' %&gt;
      &lt;% end %&gt;
  &lt;/section&gt;
  </code></pre>
  
  <p>I want the Categories list to be an autocomplete input. How do I implement this in Rails 6.  I have tried various libraries but they all are outdated.</p>