chore: fix link in readme (#1373)

README.md

@@ -11,7 +11,7 @@
 Gno is an interpreted and fully-deterministic implementation of the Go
 programming language, designed to build succinct and composable smart contracts.
 The first blockchain to use it is Gno.land, a
-[Proof of Contribution](./docs/proof-of-contribution.md)-based chain, backed by
+[Proof of Contribution](./docs/explanation/proof-of-contribution.md)-based chain, backed by
 a variation of the [Tendermint](https://docs.tendermint.com/v0.34/introduction/what-is-tendermint.html)
 consensus engine.