CLDR-17336 update convert rules for parentLocales change

- improve docs on some LdmlConvertRules items
- will refine this in CLDR-17367 at JSON build time if needed

tools/cldr-code/src/main/java/org/unicode/cldr/json/LdmlConvertRules.java

@@ -311,7 +311,8 @@ public static class SplittableAttributeSpec {
 
     /**
      * There are a handful of attribute values that are more properly represented as an array of
-     * strings rather than as a single string.
+     * strings rather than as a single string. These are not locked to a specific element, may need
+     * to change the matching algorithm if there are conflicts.
      */
     public static final Set<String> ATTRVALUE_AS_ARRAY_SET =
             Builder.with(new HashSet<String>())
@@ -320,6 +321,7 @@ public static class SplittableAttributeSpec {
                     .add("contains")
                     .add("systems")
                     .add("origin")
+                    .add("component") // for parentLocales - may need to be more specific here
                     .add("values") // for unitIdComponents - may need to be more specific here
                     .freeze();
 
@@ -382,6 +384,11 @@ public static class SplittableAttributeSpec {
             PatternCache.get(
                     "(grammaticalCase|grammaticalGender|grammaticalDefiniteness|nameOrderLocales|component)");
 
+    /**
+     * Indicates that the child value of this element needs to be separated into array items. For
+     * example: {@code <weekOfPreference ordering="weekOfDate weekOfMonth" locales="en bn ja ka"/>}
+     * becomes {@code {"en":["weekOfDate","weekOfMonth"],"bn":["weekOfDate","weekOfMonth"]} }
+     */
     public static final Set<String> CHILD_VALUE_IS_SPACESEP_ARRAY =
             ImmutableSet.of("weekOfPreference", "calendarPreferenceData");