SLING-11945 - Document the new repositoryUrls launch parameter (#15)

Document default values for the repository URLs
diff --git a/src/main/java/org/apache/sling/maven/feature/launcher/StartMojo.java b/src/main/java/org/apache/sling/maven/feature/launcher/StartMojo.java
index 6350c9e..dc18b84 100644
--- a/src/main/java/org/apache/sling/maven/feature/launcher/StartMojo.java
+++ b/src/main/java/org/apache/sling/maven/feature/launcher/StartMojo.java
@@ -93,10 +93,22 @@
      *   </framweworkProperties>
      *   ..
      * </launcherArguments>
+     * <repositoryUrls>
+     *    <repositoryUrl>file://${project.build.directory}/artifacts</repositoryUrl>
+     *    <repositoryUrl>https://repo1.maven.org/maven2/</repositoryUrl>
+     * </repositoryUrls>
      * <environmentVariables><!--additional environment variables to pass to the launcher -->
      *  <JAVA_HOME>...</JAVA_HOME>
      * </environmentVariables>}
      * </pre>
+     * 
+     * <p>The repository URLs replace the default values set by the Feature Launcher. These default values are:
+     * <ul>
+     *   <li>The local Maven repository at $HOME/.m2/repository</li>
+     *   <li>The Maven Central repository</li>
+     *   <li>The Apache Snapshots repository</li>
+     * </ul>
+     * </p>
      */
     @Parameter(required = true)
     private List<Launch> launches;