docs: Fix missing reference on documentation for InlineTextNode (#3520)

Fix missing reference on documentation for InlineTextNode

Author: luanpotter

packages/flame/lib/src/text/nodes/inline_text_node.dart

@@ -7,7 +7,8 @@ import 'package:flame/text.dart';
 /// * PlainTextNode - just a string of plain text, no special formatting.
 /// * BoldTextNode - bolded string
 /// * ItalicTextNode - italic string
-/// * CodeTextNode - inline code block
+/// * CodeTextNode - inline code string
+/// * StrikethroughTextNode - strikethrough string
 /// * GroupTextNode - collection of multiple [InlineTextNode]'s to be joined one
 ///                   after the other.
 abstract class InlineTextNode extends TextNode<InlineTextStyle> {