Returns `true` if this list contains a TAG ```rust use orgize::{Org, ast::List}; let list = Org::parse("- some tag :: item 2.1").first_node:: ().unwrap(); assert!(list.is_descriptive()); let list = Org::parse("2. [X] item 2").first_node:: ().unwrap(); assert!(!list.is_descriptive()); ```
(&self)