Update Merkle Tree Links

- Removed broken link to Notion document.
- Added new links.

Author: CimimUxMaio

README.md

@@ -719,7 +719,12 @@ We suggest starting simple, do not optimize prematurely because it's pretty sure
 Here are some sources that you might find useful:
 - [Merkle Tree - Brilliant.org](https://brilliant.org/wiki/merkle-tree/)
 - [Merkle Tree Verify in Solidity](https://www.youtube.com/watch?v=n6nEPaE7KZ8)
-- [Other resources](https://nimble-aftershave-74f.notion.site/Resources-a632c530ccfd477d9454c4345c1c554f)
+- [Merkle Tree - Brilliant.org](https://brilliant.org/wiki/merkle-tree/)
+- [Merkle Tree Verify in Solidity](https://www.youtube.com/watch?v=n6nEPaE7KZ8)
+- [Merkle Tree - Wikipedia](https://en.wikipedia.org/wiki/Merkle_tree)
+- [Merkle Tree - What is a Merkle Tree?](https://decentralizedthoughts.github.io/2020-12-22-what-is-a-merkle-tree/)
+- [Introduction to Merkle Tree - GeeksforGeeks](https://www.geeksforgeeks.org/introduction-to-merkle-tree/)
+- [Merkle Tree in Blockchain: What It Is and How It Works](https://www.investopedia.com/terms/m/merkle-tree.asp)
 
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 ### Julia