fix dead link README.md (#2312)

Co-authored-by: Kevin Yang <[email protected]>
Co-authored-by: Matthias <[email protected]>
Co-authored-by: Unique Divine <[email protected]>

Author: 4 people

x/oracle/README.md

@@ -4,7 +4,7 @@ The Oracle module provides the Nibiru blockchain with an up-to-date and accurate
 
 As price information is extrinsic to the blockchain, the Nibiru network relies on validators to periodically vote on the current exchange rates, with the protocol tallying up the results once per `VotePeriod` and updating the on-chain exchange rate as the weighted median of the ballot.
 
-> Since the Oracle service is powered by validators, you may find it interesting to look at the [Staking](https://github.com/cosmos/cosmos-sdk/tree/master/x/staking/spec/README.md) module, which covers the logic for staking and validators.
+> Since the Oracle service is powered by validators, you may find it interesting to look at the [Staking](https://github.com/cosmos/cosmos-sdk/blob/main/x/staking/README.md) module, which covers the logic for staking and validators.
 
 ## Contents         <!-- omit in toc -->
 - [Oracle](#oracle)