Use isEmpty for size check & fix missing noun reported by spell check (#358)

Co-authored-by: Patrick Kleindienst <[email protected]>

Author: apophizzz

ktoml-core/src/commonMain/kotlin/com/akuleshov7/ktoml/tree/nodes/TomlNode.kt

@@ -57,9 +57,9 @@ public sealed class TomlNode(
     )
 
     /**
-     * @return true if has no children
+     * @return true if node has no children
      */
-    public fun hasNoChildren(): Boolean = children.size == 0
+    public fun hasNoChildren(): Boolean = children.isEmpty()
 
     /**
      * @return first child or null