Document how to override plugin configuration on the command line

Closes gh-21536

Author: snicoll

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/asciidoc/using.adoc

@@ -106,3 +106,45 @@ For instance, to use a different version of the SLF4J library and the Spring Dat
 ----
 
 
+
+[[using-overriding-command-line]]
+=== Overriding settings on the command-line
+The plugin offers a number of user properties, starting with `spring-boot`, to let you customize the configuration from the command-line.
+
+For instance, you could tune the profiles to enable when running the application as follows:
+
+[indent=0]
+----
+	$ mvn spring-boot:run -Dspring-boot.run.profiles=dev,local
+----
+
+If you want to both have a default while allowing it to be overridden on the command-line, you should use a combination of a user-provided project property and MOJO configuration.
+
+[source,xml,indent=0,subs="verbatim,attributes"]
+----
+<project>
+    <properties>
+        <app.profiles>local,dev</app.profiles>
+    </properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<version>{gradle-project-version}</version>
+				<configuration>
+					<profiles>${app.profiles}</profiles>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+</project>
+----
+
+The above makes sure that `local` and `dev` are enabled by default.
+Now a dedicated property has been exposed, this can be overridden on the command-line as well:
+
+[indent=0]
+----
+	$ mvn spring-boot:run -Dapp.profiles=test
+----