Enabled XML docs.

src/MapTo/MapTo.csproj

@@ -20,6 +20,14 @@
         <RootNamespace>MapTo</RootNamespace>
     </PropertyGroup>
 
+    <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
+      <DocumentationFile>bin\Debug\MapTo.xml</DocumentationFile>
+    </PropertyGroup>
+
+    <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+      <DocumentationFile>bin\Release\MapTo.xml</DocumentationFile>
+    </PropertyGroup>
+
     <ItemGroup>
         <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
             <_Parameter1>$(AssemblyName).Tests</_Parameter1>

src/MapTo/MapToGenerator.cs

@@ -7,6 +7,9 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace MapTo
 {
+    /// <summary>
+    /// MapTo source generator.
+    /// </summary>
     [Generator]
     public class MapToGenerator : ISourceGenerator
     {

src/MapTo/Sources/SourceBuilder.cs

@@ -4,7 +4,7 @@ using System.IO;
 
 namespace MapTo.Sources
 {
-    public sealed class SourceBuilder : IDisposable
+    internal sealed class SourceBuilder : IDisposable
     {
         private readonly StringWriter _writer;
         private readonly IndentedTextWriter _indentedWriter;