Update to use new {!snippet:...} syntax

README.md

-<!-- See expanded [macro:...] values at https://github.com/springframework-meta/springframework.org/tree/master/doc/gs-macros.md -->
-
 # Getting Started: Building a RESTful Web Service
 
 What you'll build
 ----------------
 
  - About 15 minutes
- - [macro:prereq-editor-jdk-buildtools]
+ - {!snippet:prereq-editor-jdk-buildtools}
 
-## [macro:how-to-complete-this-guide]
+## {!snippet:how-to-complete-this-guide}
 
 
 <a name="scratch"></a>
 Set up the project
 ------------------
 
-[macro:build-system-intro]
+{!snippet:build-system-intro}
 
-[macro:create-directory-structure-hello]
+{!snippet:create-directory-structure-hello}
 
 ### Create a Maven POM
 
-[macro:maven-project-setup-options]
+{!snippet:maven-project-setup-options}
 
 `pom.xml`
 ```xml
 </project>
 ```
 
-[macro:bootstrap-starter-pom-disclaimer]
+{!snippet:bootstrap-starter-pom-disclaimer}
 
 
 <a name="initial"></a>
 
 The [`@EnableAutoConfiguration`][] annotation switches on reasonable default behaviors based on the content of your classpath. For example, because the application depends on the embeddable version of Tomcat (tomcat-embed-core.jar), a Tomcat server is set up and configured with reasonable defaults on your behalf. And because the application also depends on Spring MVC (spring-webmvc.jar), a Spring MVC [`DispatcherServlet`][] is configured and registered for you — no `web.xml` necessary! Auto-configuration is a powerful, flexible mechanism. See the [API documentation][`@EnableAutoConfiguration`] for further details.
 
-### [macro:build-an-executable-jar]
+### {!snippet:build-an-executable-jar}
 
 
 Run the service