doc(trait): Add some documentation on maven profile trait

Ref #4560

docs/modules/ROOT/pages/configuration/maven-profile.adoc

@@ -0,0 +1,24 @@
+= Maven Profile
+
+You can customize the build of an integration with a https://maven.apache.org/guides/introduction/introduction-to-profiles.html#profiles-in-poms[Maven profile]:
+
+```
+<profile>
+  <id>my-profile</id>
+  ...
+</profile>
+```
+
+Once you have the file ready you can create a Configmap or a Secret in order to use it in your integration:
+
+```
+kubectl create cm my-maven-profile --from-file my-profile.xml
+```
+
+Once the Configmap/Secret is ready, then, you can use it to run your integration:
+
+```
+kamel run hello.groovy -t builder.maven-profile=configmap:my-maven-profile/my-profile.xml
+```
+
+The profile will be added to your integration's project generated pom file. What will be changed in the `mvn package` execution will depend on your profile definition.