Mention Gradle build in readme

Author: Dave Syer

readme.md

@@ -26,6 +26,8 @@ Or you can run it from Maven directly using the Spring Boot Maven plugin. If you
 
 > NOTE: Windows users should set `git config core.autocrlf true` to avoid format assertions failing the build (use `--global` to set that flag globally).
 
+> NOTE: If you prefer to use Gradle, you can build the app using `./gradlew build` and look for the jar file in `build/libs`.
+
 ## In case you find a bug/suggested improvement for Spring Petclinic
 Our issue tracker is available here: https://github.com/spring-projects/spring-petclinic/issues
 
@@ -50,7 +52,7 @@ and for [PostgreSQL](https://github.com/spring-projects/spring-petclinic/blob/ma
 
 ## Compiling the CSS
 
-There is a `petclinic.css` in `src/main/resources/static/resources/css`. It was generated from the `petclinic.scss` source, combined with the [Bootstrap](https://getbootstrap.com/) library. If you make changes to the `scss`, or upgrade Bootstrap, you will need to re-compile the CSS resources using the Maven profile "css", i.e. `./mvnw package -P css`.
+There is a `petclinic.css` in `src/main/resources/static/resources/css`. It was generated from the `petclinic.scss` source, combined with the [Bootstrap](https://getbootstrap.com/) library. If you make changes to the `scss`, or upgrade Bootstrap, you will need to re-compile the CSS resources using the Maven profile "css", i.e. `./mvnw package -P css`. There is no build profile for Gradle to compile the CSS.
 
 ## Working with Petclinic in your IDE