title: MVC 6 Anchor Tag Helper not producing the expected href
body: <p>Fairly straightforward issue. </p>
  
  <pre><code>&lt;a asp-controller="Guide" asp-action="Index" asp-route-title="@Model.Title"&gt;Read more&lt;/a&gt;
  </code></pre>
  
  <p>produces the link <strong><em>/Guide?title=Guide_no_1</em></strong> but it is supposed to produce the link <strong><em>/Guide/Guide_no_1/</em></strong></p>
  
  <p>The documentation i can find all specify that its supposed to output <strong><em>/Guide/Guide_no_1/</em></strong> so I have the feeling there is something i missed, a setting or some attribute somewhere.</p>
  
  <p>the routes i have are like this, just incase they have an impact on link creation</p>
  
  <pre><code>[Route("/Guide/")]
  public IActionResult Index() { ... }
  
  [Route("/Guide/{title}/{page?}/")]
  public IActionResult Index(string title, int page = 0) { ... }
  
  [Route("/Guide/OnePage/{title}/")]
  public IActionResult Index(string title) { ... }
  </code></pre>