move old resources from protocol toolkit

zero_knowledge/zkEVMs/zkSync/README.md

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+## zkSync
+
+<br>
+
+### tl; dr
+
+<br>
+
+* layer-2 scaling solution for ethereum, aiming for scalability. 
+* zkSync 2 is called Era, zkSync 1 is called light.
+* uses "optimistic" transfers, which allow users to send and receive txs without waiting for conformation (reducing tx times, and allowing higher tx throughput).
+* tvl: zkSync era has higher transfers of assets ($125M) than Polygon zkEVM ($2.57M) 
+* sybil addresses: zkSync era has more potential sybil addresses based on the depositing addresses’ wallet age and usage on Ethereum/Layer 2 networks. 
+* tx costs: ~$0.25-$2, high compared to optimistic rollups like arbitrum and Ootimism ($0.13 - $0.45)
+
+<br>
+
+----
+
+### zksync era
+
+* zksync era archtecture:
+  * native account abstraction (any account on era can pay fees in any tokens or even transact with zero fees on protocols willing to subsidize usage)
+  * powerful llvm compiler
+  * data compression (publishing states diffs instead of tx inputs, enabling data compression, more frequent oracle updates, cheap privacy, seamless off-chain sotrage extension)
+  * hyperscalability 
+
+
+<br>
+
+----
+
+### cool resources
+
+<br>
+
+* **[zksync ecosystem](https://ecosystem.zksync.io/)**
+* **[gm zkEVM, by zksync](https://blog.matter-labs.io/gm-zkevm-171b12a26b36)**
+* **[dune board zksync vs. polygon zkEVM](https://dune.com/21shares_research/zkevm-comparison-zksync-era-vs-polygon-hermez)**