fix links

Author: 0xValera

CONTRIBUTING.md

@@ -33,8 +33,8 @@ license.
 We aim to make it as easy as possible to contribute to the mission. This is still WIP, and we're happy for contributions
 and suggestions here too. Some resources to help:
 
-1. [In-repo docs aimed at developers](docs)
-2. [ZKsync Era docs!](https://docs.zksync.io/zk-stack)
+1. [Docs aimed at developers](https://docs.zksync.io/zksync-protocol)
+2. [ZK Stack docs!](https://docs.zksync.io/zk-stack)
 3. Company links can be found in the [repo's readme](README.md)
 
 ## Code of Conduct

README.md

@@ -8,7 +8,7 @@ or re-auditing a single line of code. ZKsync Era also uses an LLVM-based compile
 write smart contracts in C++, Rust and other popular languages.
 
 This repository contains both L1 and L2 ZKsync smart contracts. For their description see the
-[system overview](docs/overview.md).
+[contracts overview](https://docs.zksync.io/zksync-protocol/contracts).
 
 ## Disclaimer