Fix formatting errors

Author: RehanSaeed

Source/Boxed.AspNetCore.TagHelpers/Twitter/Structs/TwitterPlayer.cs

@@ -17,7 +17,7 @@ public class TwitterPlayer
         /// </param>
         /// <param name="width">The width of the iFrame player in pixels.</param>
         /// <param name="height">The height of the iFrame player in pixels.</param>
-        /// <exception cref="ArgumentNullException"><paramref name="playerUrl"/></exception>
+        /// <exception cref="ArgumentNullException">The <paramref name="playerUrl"/> is <c>null</c>.</exception>
         /// <exception cref="ArgumentOutOfRangeException">
         /// <paramref name="width"/> and <paramref name="height"/> must be more than zero.
         /// </exception>
@@ -59,7 +59,7 @@ public TwitterPlayer(string playerUrl, int width, int height)
         /// audio and video with the following codecs: Video: H.264, Baseline Profile(BP), Level 3.0, up to 640 x 480 at
         /// 30 fps. Audio: AAC, Low Complexity Profile(LC).
         /// </param>
-        /// <exception cref="ArgumentNullException"><paramref name="playerUrl"/></exception>
+        /// <exception cref="ArgumentNullException">The <paramref name="playerUrl"/> is <c>null</c>.</exception>
         /// <exception cref="ArgumentOutOfRangeException">
         /// <paramref name="width"/> and <paramref name="height"/> must be more than zero.
         /// </exception>

Source/Boxed.AspNetCore/ConfigurationExtensions.cs

@@ -4,7 +4,7 @@ namespace Boxed.AspNetCore
     using Microsoft.Extensions.Configuration;
 
     /// <summary>
-    /// <see cref="IConfiguration"/>
+    /// <see cref="IConfiguration"/> extension methods.
     /// </summary>
     public static class ConfigurationExtensions
     {

Source/Boxed.AspNetCore/FriendlyUrlHelper.cs

@@ -56,6 +56,7 @@ public static class FriendlyUrlHelper
         ///     return this.View(product);
         /// }
         /// </c>
+        /// .
         /// </code>
         public static string GetFriendlyTitle(string title, bool remapToAscii = false, int maxlength = 80)
         {

Source/Boxed.AspNetCore/IAsyncCommand{T}.cs

@@ -7,7 +7,7 @@ namespace Boxed.AspNetCore
     /// <summary>
     /// Executes a single command with one parameter and returns a result.
     /// </summary>
-    /// <typeparam name="T">The type of the parameter</typeparam>
+    /// <typeparam name="T">The type of the parameter.</typeparam>
     public interface IAsyncCommand<T>
     {
         /// <summary>