Honor the odd startup setting from org-mode files.

src/parser/in_buffer_settings.rs

@@ -81,6 +81,9 @@ pub(crate) fn apply_in_buffer_settings<'g, 's, 'sf>(
         if settings.contains(&"odd") {
             new_settings.odd_levels_only = HeadlineLevelFilter::Odd;
         }
+        if settings.contains(&"oddeven") {
+            new_settings.odd_levels_only = HeadlineLevelFilter::OddEven;
+        }
     }
 
     Ok(new_settings)