feat(oxc_ast): wrote document about VariableDeclaration

crates/oxc_ast/src/ast/js.rs

@@ -1831,7 +1831,9 @@ impl<'a> Declaration<'a> {
     }
 }
 
-/// Variable Declaration
+/// `let a;` in `let a; a = 1;`
+///
+/// Represents a variable declaration, which can include a kind, declarations, and modifiers.
 #[visited_node]
 #[derive(Debug, Hash)]
 #[cfg_attr(feature = "serialize", derive(Serialize, Tsify))]