docs(notes): update data link layer notes

Author: lzwjava

Diff for: notes/2025-03-22-data-link-layer-en.md

@@ -11,8 +11,6 @@ Here's a detailed tutorial to help you learn the **Data Link Layer** chapter in
 
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-# **Data Link Layer: A Comprehensive Guide**  
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 ## **1. Overview of the Data Link Layer**  
 The Data Link Layer is the **second layer** in the **OSI model**, responsible for providing **reliable data transfer** between directly connected nodes. It ensures that frames (data packets at this layer) are correctly formatted, transmitted, and received.