updated readme and plugin version

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

Author: tsurdilo

README.md

@@ -34,6 +34,9 @@ git clone https://github.com/serverlessworkflow/sdk-java.git
 mvn clean install
 ```
 
+The project uses [Google's code styleguide](https://google.github.io/styleguide/javaguide.html).
+Your changes should be automatically formatted during the build.
+
 To use it in your projects you can:
 
 #### Maven projects:

pom.xml

@@ -63,7 +63,7 @@
         <version.thymeleaf>3.0.11.RELEASE</version.thymeleaf>
         <version.plantuml>8059</version.plantuml>
         <version.graphviz>0.17.0</version.graphviz>
-        <version.fmt-maven-plugin>2.12</version.fmt-maven-plugin>
+        <version.fmt-maven-plugin>2.9</version.fmt-maven-plugin>
 
         <!-- Checkstyle props -->
         <checkstyle.failOnViolation>true</checkstyle.failOnViolation>