More readable formatting in the warning advising users to not publish…

… a project having auto-named dependencies.

Note: this warning is questionable. Should it be removed?

maven-api-impl/src/main/java/org/apache/maven/internal/impl/PathModularizationCache.java

@@ -178,10 +178,11 @@ Optional<String> warningForFilenameBasedAutomodules(Collection<Path> modulePaths
         if (automodulesDetected.isEmpty()) {
             return Optional.empty();
         }
+        String lineSeparator = System.lineSeparator();
         var joiner = new StringJoiner(
-                ", ",
-                "Filename-based automodules detected on the module-path: ",
-                "Please don't publish this project to a public artifact repository.");
+                lineSeparator + "  - ",
+                "Filename-based automodules detected on the module-path: " + lineSeparator + "  - ",
+                lineSeparator + "Please don't publish this project to a public artifact repository.");
         automodulesDetected.forEach(joiner::add);
         return Optional.of(joiner.toString());
     }