Clarify usage of run.arguments with Maven plugin

spring-boot-docs/src/main/asciidoc/build-tool-plugins.adoc

@@ -273,7 +273,7 @@ The following configuration options are available for the `spring-boot:run` goal
 |Name |Description
 
 |`arguments` or `-Drun.arguments`
-|Arguments that should be passed to the application.
+|Arguments that should be passed to the application (comma-separated).
 
 |`addResources` or `-Drun.addResources`
 |Add Maven resources to the classpath directly, this allows live in-place editing or

spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RunMojo.java

@@ -78,7 +78,8 @@ public class RunMojo extends AbstractMojo {
 	private Boolean noverify;
 
 	/**
-	 * Arguments that should be passed to the application.
+	 * Arguments that should be passed to the application. On command line use commas to
+	 * separate multiple arguments.
 	 */
 	@Parameter(property = "run.arguments")
 	private String[] arguments;