Expand Error Handling section in docs a bit

Fixes gh-513

spring-boot-docs/src/main/asciidoc/production-ready-features.adoc

@@ -740,10 +740,41 @@ if needed.
 
 [[production-ready-error-handling]]
 == Error Handling
-Spring Boot Actuator provides an `/error` mapping by default that handles all errors in a
-sensible way.  If you want more specific error pages for some conditions, the embedded
-servlet containers support a uniform Java DSL for customizing the error handling.
 
+Spring Boot Actuator provides an `/error` mapping by default that
+handles all errors in a sensible way, and it is registered as a
+"global" error page in the servlet container. For machine clients it
+will produce a JSON response with details of the error, the HTTP
+status and the exception message. For browser clients there is a
+"whitelabel" error view that renders the same data in HTML format (to
+customize it just add a `View` that resolves to ``error'').
+
+If you want more specific error
+pages for some conditions, the embedded servlet containers support a
+uniform Java DSL for customizing the error handling. For example:
+
+[source,java,indent=0,subs="verbatim,quotes,attributes"]
+----
+	@Bean
+	public EmbeddedServletContainerCustomizer containerCustomizer(){
+		return new MyCustomizer();
+	}
+
+	// ...
+
+	private static class MyCustomizer implements EmbeddedServletContainerCustomizer {
+
+		@Override
+		public void customize(ConfigurableEmbeddedServletContainer factory) {
+            factory.addErrorPages(new ErrorPage(HttpStatus.BAD_REQUEST, "/400"));
+		}
+
+	}
+----
+
+
+You can also use regular Spring MVC features like http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#mvc-exception-handlers[`@ExceptionHandler`
+methods] and http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#mvc-ann-controller-advice[`@ControllerAdvice`].
 
 
 [[production-ready-process-monitoring]]