8281445: Document the default value for the override-methods option

Reviewed-by: prappo

Author: jonathan-gibbons

src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/resources/standard.properties

@@ -629,7 +629,8 @@ doclet.usage.override-methods.parameters=\
     (detail|summary)
 
 doclet.usage.override-methods.description=\
-    Document overridden methods in the detail or summary sections
+    Document overridden methods in the detail or summary sections.\n\
+    The default is 'detail'.
 
 doclet.usage.allow-script-in-comments.description=\
     Allow JavaScript in options and comments