Add etherscan verification plugin and docs

.env.example

@@ -1,2 +1,3 @@
 RINKEBY_PRIVATE_KEY=
 ALCHEMY_PROJECT_ID=
+ETHERSCAN_API_KEY=

README.md

@@ -78,3 +78,10 @@ The coverage report will then be found in `coverage/`.
 To deploy to the [rinkeby network](https://www.rinkeby.io/) you need to set appropriate environment variables. The file [.env.example](.env.example) contains examples of the variables you need to set. For convenience you can copy this file to a file name _.env_ and use a tool like [direnv](https://direnv.net/) to automatically load it.
 
 You could then deploy to rinkeby by using [hardhat-deploy](https://github.com/wighawag/hardhat-deploy) with this command `yarn hardhat deploy --network rinkeby`.
+
+### Verifying contracts
+
+To verify the contracts on rinkeby you will need an etherscan API key, see [.env.example](.env.example). To verify a contract on you will need the deployed contracts address, run
+```
+yarn hardhat verify --network rinkeby "${contract_address}"
+```

hardhat.config.js

@@ -1,4 +1,5 @@
 require("@nomiclabs/hardhat-ethers");
+require("@nomiclabs/hardhat-etherscan");
 require("@nomiclabs/hardhat-waffle");
 require("@openzeppelin/hardhat-upgrades");
 require("hardhat-abi-exporter");
@@ -37,4 +38,7 @@ module.exports = {
     deployer: 0,
     dev: 1,
   },
+  etherscan: {
+    apiKey: process.env.ETHERSCAN_API_KEY
+  }
 };

package.json

@@ -24,6 +24,7 @@
   "homepage": "https://github.com/traderjoe-xyz/rocker-joe/issues",
   "devDependencies": {
     "@nomiclabs/hardhat-ethers": "^2.0.0",
+    "@nomiclabs/hardhat-etherscan": "^3.0.0",
     "@nomiclabs/hardhat-waffle": "^2.0.0",
     "@openzeppelin/contracts": "^4.4.1",
     "@openzeppelin/contracts-upgradeable": "^4.4.1",