Update README.md

- Change admonition style to use blockquote syntax

README.md

 
 The `@RequestMapping` annotation ensures that HTTP requests to `/greeting` are mapped to the `greeting()` method.
 
-[admon:note] We have not explicitly specified `GET` vs. `PUT`, `POST`, etc. above, because `@RequestMapping` maps _all_ HTTP operations by default. Use `@RequestMapping(method=GET)` to narrow this down.
+> **Note:** We have not explicitly specified `GET` vs. `PUT`, `POST`, etc. above, because `@RequestMapping` maps _all_ HTTP operations by default. Use `@RequestMapping(method=GET)` to narrow this down.
 
 `@RequestParam` binds the value of the query string parameter `name` into the `name` parameter of the `greeting()` method. This query string parameter is not `required`, so if absent in the request the `defaultValue` of "World" will be used.
 
 [`@Component`]: http://static.springsource.org/spring/docs/current/javadoc-api/org/springframework/stereotype/Component.html
 [`@ResponseBody`]: http://static.springsource.org/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/ResponseBody.html
 [`MappingJackson2HttpMessageConverter`]: http://static.springsource.org/spring/docs/current/javadoc-api/org/springframework/http/converter/json/MappingJackson2HttpMessageConverter.html
-[`DispatcherServlet`]: http://static.springsource.org/spring/docs/current/javadoc-api/org/springframework/web/servlet/DispatcherServlet.html
+[`DispatcherServlet`]: http://static.springsource.org/spring/docs/current/javadoc-api/org/springframework/web/servlet/DispatcherServlet.html