Fix case in link from why move to .move file (MystenLabs#2575)

doc/src/learn/why-move.md

@@ -18,4 +18,4 @@ Sui heavily leverages the Move data model for performance. Sui's persistent stat
 
 This is simply not possible with the EVM data model. Because assets are stored in dynamically indexable maps, a validator would be unable to determine when transactions might touch the same asset. Sui's parallel execution and commitment scheme needs a language like Move with the vocabulary to describe structured assets that can flow freely across contracts. To be blunt: **even if we preferred the EVM/Solidity to Move, we could not use them in Sui without sacrificing the performance breakthroughs that make Sui unique**.
 
-One of the main advantages of Move is data composability. It is always possible to create a new struct (asset) Y that will hold initial asset X in it. Even more - with addition of generics, it is possible to define generic wrapper Z(T) that will be able to wrap any asset, providing additional properties to a wrapped asset or combining it with others. See how composability works in our [Sandwich example](https://github.com/MystenLabs/sui/tree/main/sui_programmability/examples/basics/sources/Sandwich.move).
+One of the main advantages of Move is data composability. It is always possible to create a new struct (asset) Y that will hold initial asset X in it. Even more - with addition of generics, it is possible to define generic wrapper Z(T) that will be able to wrap any asset, providing additional properties to a wrapped asset or combining it with others. See how composability works in our [Sandwich example](https://github.com/MystenLabs/sui/tree/main/sui_programmability/examples/basics/sources/sandwich.move).