Cross link Actuator and User Guide docs

Not having READMEs in github is a mistake IMO, so here's one
restored and with a link to the docs. Docs also updated to
more accurately reflect the location of the actuator features
in implementation.

See https://github.com/spring-guides/gs-actuator-service/pull/7
for the Getting started guide change

Fixes gh-1014

spring-boot-actuator/README.md

@@ -0,0 +1,59 @@
+# Spring Boot - Actuator
+
+Spring Boot Actuator includes a number of additional features to help
+you monitor and manage your application when it's pushed to
+production. You can choose to manage and monitor your application
+using HTTP endpoints, with JMX or even by remote shell (SSH or
+Telnet).  Auditing, health and metrics gathering can be automatically
+applied to your application. The
+[user guide](http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#production-ready)
+covers the features in more detail.
+
+## Enabling the Actuator
+
+The simplest way to enable the features is to add a dependency to the
+`spring-boot-starter-actuator` "Starter POM". To add the actuator to a
+Maven based project, add the following "starter" dependency:
+
+```xml
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+		</dependency>
+	</dependencies>
+```
+
+For Gradle, use the declaration:
+
+```groovy
+	dependencies {
+		compile("org.springframework.boot:spring-boot-starter-actuator")
+	}
+```
+
+## Features
+
+* **Endpoints** Actuator endpoints allow you to monitor and interact
+with your application. Spring Boot includes a number of built-in
+endpoints and you can also add your own. For example the `health`
+endpoint provides basic application health information. Run up a basic
+app and look at "/health" (and see "/mappings" for a list of other
+HTTP endpoints).
+
+* **Metrics** Spring Boot Actuator includes a metrics service with
+"gauge" and "counter" support.  A "gauge" records a single value; and
+a "counter" records a delta (an increment or decrement). Metrics for
+all HTTP requests are automatically recorded, so if you hit the
+`metrics` endpoint should should see a response similar to this:
+
+* **Audit** Spring Boot Actuator has a flexible audit framework that
+will publish events to an `AuditService`. Once Spring Security is in
+play it automatically publishes authentication events by default. This
+can be very useful for reporting, and also to implement a lock-out
+policy based on authentication failures.
+
+* **Process Monitoring** In Spring Boot Actuator you can find
+`ApplicationPidListener` which creates file containing application PID
+(by default in application directory and file name is
+`application.pid`).

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

@@ -1,5 +1,5 @@
 [[production-ready]]
-= Production-ready features
+= Spring Boot Actuator: Production-ready features
 
 [partintro]
 --
@@ -13,7 +13,7 @@ Auditing, health and metrics gathering can be automatically applied to your appl
 
 [[production-ready-enabling]]
 == Enabling production-ready features.
-The `spring-boot-actuator` module provides all of Spring Boot's production-ready
+The https://github.com/spring-projects/spring-boot/tree/master/spring-boot-actuator[`spring-boot-actuator`] module provides all of Spring Boot's production-ready
 features. The simplest way to enable the features is to add a dependency to the
 `spring-boot-starter-actuator` ``Starter POM''.