Explicitly call AddOptions

Author: ronaldbarendse

src/ImageSharp.Web/DependencyInjection/ServiceCollectionExtensions.cs

@@ -37,6 +37,7 @@ public static IImageSharpBuilder AddImageSharp(this IServiceCollection services,
 
         private static IImageSharpBuilder AddDefaultServices(this IImageSharpBuilder builder)
         {
+            builder.Services.AddOptions();
             builder.Services.AddSingleton<FormatUtilities>();
             builder.Services.AddSingleton<AsyncKeyReaderWriterLock<string>>();