Add doc comments

crates/codegen/parser/runtime/src/cst.rs

@@ -46,6 +46,7 @@ impl Node {
         }
     }
 
+    /// Returns a slice of the children (not all descendants) of this node.
     pub fn children(&self) -> &[Node] {
         match self {
             Self::Rule(node) => &node.children,

crates/codegen/parser/runtime/src/cursor.rs

@@ -144,6 +144,7 @@ impl Cursor {
         self.current.text_range()
     }
 
+    /// Returns the depth of the current node in the CST, i.e. the number of ancestors.
     pub fn depth(&self) -> usize {
         self.path.len()
     }