Update Lecture2.md

Author: benpaddlejones

tutorials/Lecture2.md

@@ -10,7 +10,7 @@
 What is a UML Class Diagram?
 A UML (Unified Modelling Language) class diagram visually describes the structure of a system by showing its classes, their attributes (variables), methods (functions), and relationships (like inheritance).
 
-```txt
+```text
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 |     Student       |   <-- Class Name
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