Generate documentation XML when building; fix errors.

Author: bgrainger

src/Directory.Build.props

@@ -17,6 +17,8 @@
     <LangVersion>8.0</LangVersion>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <NoWarn>1591</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

src/MySqlConnector/Core/ICancellableCommand.cs

@@ -26,7 +26,7 @@ internal static class ICancellableCommandExtensions
 		public static int GetNextId() => Interlocked.Increment(ref s_id);
 
 		/// <summary>
-		/// Causes the effective command timeout to be reset back to the value specified by <see cref="CommandTimeout"/>.
+		/// Causes the effective command timeout to be reset back to the value specified by <see cref="ICancellableCommand.CommandTimeout"/>.
 		/// </summary>
 		/// <remarks>As per the <a href="https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.commandtimeout.aspx">MSDN documentation</a>,
 		/// "This property is the cumulative time-out (for all network packets that are read during the invocation of a method) for all network reads during command

src/MySqlConnector/Utilities/Utility.cs

@@ -215,11 +215,12 @@ public static ArraySegment<T> Slice<T>(this ArraySegment<T> arraySegment, int in
 			new ArraySegment<T>(arraySegment.Array!, arraySegment.Offset + index, length);
 
 		/// <summary>
-		/// Returns a new <see cref="byte[]"/> that is a slice of <paramref name="input"/> starting at <paramref name="offset"/>.
+		/// Returns a new <see cref="T:byte[]"/> that is a slice of <paramref name="input"/> starting at <paramref name="offset"/>.
 		/// </summary>
 		/// <param name="input">The array to slice.</param>
 		/// <param name="offset">The offset at which to slice.</param>
-		/// <returns>A new <see cref="byte[]"/> that is a slice of <paramref name="input"/> from <paramref name="offset"/> to the end.</returns>
+		/// <param name="length">The length of the slice.</param>
+		/// <returns>A new <see cref="T:byte[]"/> that is a slice of <paramref name="input"/> from <paramref name="offset"/> to the end.</returns>
 		public static byte[] ArraySlice(byte[] input, int offset, int length)
 		{
 			if (offset == 0 && length == input.Length)