README.md: point Go API reference link to pkg.go.dev (#21321)

Author: tiendo1011

README.md

@@ -4,7 +4,7 @@ Official Golang implementation of the Ethereum protocol.
 
 [![API Reference](
 https://camo.githubusercontent.com/915b7be44ada53c290eb157634330494ebe3e30a/68747470733a2f2f676f646f632e6f72672f6769746875622e636f6d2f676f6c616e672f6764646f3f7374617475732e737667
-)](https://godoc.org/github.com/ethereum/go-ethereum)
+)](https://pkg.go.dev/github.com/ethereum/go-ethereum?tab=doc)
 [![Go Report Card](https://goreportcard.com/badge/github.com/ethereum/go-ethereum)](https://goreportcard.com/report/github.com/ethereum/go-ethereum)
 [![Travis](https://travis-ci.org/ethereum/go-ethereum.svg?branch=master)](https://travis-ci.org/ethereum/go-ethereum)
 [![Discord](https://img.shields.io/badge/discord-join%20chat-blue.svg)](https://discord.gg/nthXNEv)
@@ -108,7 +108,7 @@ accounts available between them.*
 
 ### Full node on the Rinkeby test network
 
-Go Ethereum also supports connecting to the older proof-of-authority based test network 
+Go Ethereum also supports connecting to the older proof-of-authority based test network
 called [*Rinkeby*](https://www.rinkeby.io) which is operated by members of the community.
 
 ```shell
@@ -117,10 +117,10 @@ $ geth --rinkeby console
 
 ### Full node on the Ropsten test network
 
-In addition to Görli and Rinkeby, Geth also supports the ancient Ropsten testnet. The 
+In addition to Görli and Rinkeby, Geth also supports the ancient Ropsten testnet. The
 Ropsten test network is based on the Ethash proof-of-work consensus algorithm. As such,
 it has certain extra overhead and is more susceptible to reorganization attacks due to the
-network's low difficulty/security. 
+network's low difficulty/security.
 
 ```shell
 $ geth --ropsten console