title: Swagger response description not shown
body: <p>I am currently attempting to display a description of a particular response in Swagger UI, but there doesn't seem to be a documentation that truly covers all aspects of that, and all the examples I've tried from <a href="https://docs.microsoft.com/en-us/aspnet/core/tutorials/getting-started-with-swashbuckle?view=aspnetcore-3.1&amp;tabs=visual-studio" rel="noreferrer">Get started with Swashbuckle and ASP.NET Core</a> don't work in .NET Core 3.1...</p>
  
  <pre class="lang-cs prettyprint-override"><code>        /// &lt;summary&gt;
          /// Test route...
          /// &lt;/summary&gt;
          /// &lt;returns&gt;&lt;/returns&gt;
          /// &lt;response code="200"&gt;This is a test&lt;/response&gt;
          [HttpGet]
          [ProducesResponseType(typeof(string), StatusCodes.Status200OK)]
          public IActionResult Get()
          {
              return Ok("Hello World");
          }
  </code></pre>
  
  <p>My .csproj contains the following as well:</p>
  
  <pre class="lang-xml prettyprint-override"><code>  &lt;PropertyGroup&gt;
      &lt;GenerateDocumentationFile&gt;true&lt;/GenerateDocumentationFile&gt;
      &lt;NoWarn&gt;$(NoWarn);1591&lt;/NoWarn&gt;
    &lt;/PropertyGroup&gt;
  </code></pre>
  
  <p>The Swagger UI ends up looking like this (and as you can see, the "Descriptipn" column doesn't contain the "This is a test" text as it probably should). Am I missing something?</p>
  
  <p><a href="https://i.stack.imgur.com/xlUwD.png" rel="noreferrer"><img src="https://i.stack.imgur.com/xlUwD.png" alt="Image preview"></a></p>
  
  <p>I also had added <code>[SwaggerResponse(StatusCodes.Status200OK, ...)]</code> to it, but nothing changes.</p>