fixed the broken link

Author: ameeetgaikwad

src/content/developers/docs/scaling/optimistic-rollups/index.md

@@ -260,6 +260,6 @@ Multiple implementations of Optimistic rollups exist that you can integrate into
 - [How do optimistic rollups work (The Complete guide)](https://www.alchemy.com/overviews/optimistic-rollups)
 - [Everything you need to know about Optimistic Rollup](https://research.paradigm.xyz/rollups)
 - [The Essential Guide to Arbitrum](https://newsletter.banklesshq.com/p/the-essential-guide-to-arbitrum)
-- [How does Optimism's Rollup really work?](https://research.paradigm.xyz/optimism)
+- [How does Optimism's Rollup really work?](https://www.paradigm.xyz/2021/01/how-does-optimisms-rollup-really-work)
 - [OVM Deep Dive](https://medium.com/ethereum-optimism/ovm-deep-dive-a300d1085f52)
 - [What is the Optimistic Virtual Machine?](https://www.alchemy.com/overviews/optimistic-virtual-machine)