Update agglayer.md

updates on credits

Author: 0xgraciegrace

docs/learn/agglayer.md

@@ -242,7 +242,8 @@ The AggLayer will allow a single ZK proof to verify state across all chains in t
 
 !!! credits
 
-    The contents of this document were sourced from [a blog post] originally written by Brendan Farmer, Co-founder @ Polygon on Sep 2023.
+    The contents of this document were initially sourced from blog post [the HackMD post]https://hackmd.io/@QOKsDTFRSd-1oYqrNQ3fIA/Hkx9X3jah originally written by Brendan Farmer, Co-founder @ Polygon on Oct 2023, and updated using a more recently blog post [the Mirror post] https://mirror.xyz/0xfa892B19c72c2D2C6B10dFce8Ff8E7a955b58A61/TXMyZhhRFa-bjr7YHwmJpKBwt2-_ysirbh_VpNy3qZY with additional details.
+
 
 
 [^1]: Definition taken from "Shared Sequencing: Defragmenting the L2 Rollup Ecosystem" https://hackmd.io/@EspressoSystems/SharedSequencing by Espresso Systems