Correct naming & docs for AddEntityFrameworkNpgsql

See https://github.com/MiniProfiler/dotnet/issues/433#issuecomment-558328803

src/EFCore.PG/Extensions/NpgsqlServiceCollectionExtensions.cs

 using JetBrains.Annotations;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Diagnostics;
 using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Metadata.Conventions.Infrastructure;
 using Microsoft.EntityFrameworkCore.Migrations;
 using Microsoft.EntityFrameworkCore.Query;
-using Microsoft.EntityFrameworkCore.Query.Internal;
 using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
 using Microsoft.EntityFrameworkCore.Update;
@@ -31,36 +31,24 @@ namespace Microsoft.Extensions.DependencyInjection
     /// Provides extension methods to configure Entity Framework Core for Npgsql.
     /// </summary>
     // ReSharper disable once UnusedMember.Global
-    public static class NpgsqlEntityFrameworkServicesBuilderExtensions
+    public static class NpgsqlServiceCollectionExtensions
     {
         /// <summary>
         ///     <para>
         ///         Adds the services required by the Npgsql database provider for Entity Framework
-        ///         to an <see cref="IServiceCollection" />. You use this method when using dependency injection
-        ///         in your application, such as with ASP.NET. For more information on setting up dependency
-        ///         injection, see http://go.microsoft.com/fwlink/?LinkId=526890.
+        ///         to an <see cref="IServiceCollection" />.
         ///     </para>
         ///     <para>
-        ///         You only need to use this functionality when you want Entity Framework to resolve the services it uses
-        ///         from an external <see cref="IServiceCollection" />. If you are not using an external
-        ///         <see cref="IServiceCollection" /> Entity Framework will take care of creating the services it requires.
+        ///         Calling this method is no longer necessary when building most applications, including those that
+        ///         use dependency injection in ASP.NET or elsewhere.
+        ///         It is only needed when building the internal service provider for use with
+        ///         the <see cref="DbContextOptionsBuilder.UseInternalServiceProvider" /> method.
+        ///         This is not recommend other than for some advanced scenarios.
         ///     </para>
         /// </summary>
-        /// <example>
-        ///     <code>
-        ///         public void ConfigureServices(IServiceCollection services)
-        ///         {
-        ///             var connectionString = "connection string to database";
-        ///
-        ///             services
-        ///                 .AddEntityFrameworkSqlServer()
-        ///                 .AddDbContext&lt;MyContext&gt;(options => options.UseNpgsql(connectionString));
-        ///         }
-        ///     </code>
-        /// </example>
         /// <param name="serviceCollection"> The <see cref="IServiceCollection" /> to add services to. </param>
         /// <returns>
-        ///     A builder that allows further Entity Framework specific setup of the <see cref="IServiceCollection" />.
+        ///     The same service collection so that multiple calls can be chained.
         /// </returns>
         public static IServiceCollection AddEntityFrameworkNpgsql([NotNull] this IServiceCollection serviceCollection)
         {