Removed mismatched closing tag

This resolves CS1570.

Author: JeremyCaney

OnTopic.AspNetCore.Mvc/Controllers/SitemapController.cs

@@ -31,7 +31,6 @@ namespace OnTopic.AspNetCore.Mvc.Controllers {
   ///     their content types; in this case, the <see cref="Topic"/> is excluded, but its descendents are not. What content
   ///     types are excluded or skipped can be configured, respectively, by modifying the static <see cref="ExcludedContentTypes
   ///     "/> and <see cref="SkippedContentTypes"/> collections.
-  ///     </i>.
   ///   </para>
   ///   <para>
   ///     The <see cref="Extended(Boolean)"/> action enables an extended sitemap with Google's custom <c>PageMap</c> schema for