Add a flattening script

.eslintignore

@@ -17,3 +17,5 @@ dist
 gas_report
 
 contracts/vendor
+
+*.flat.sol

.gitignore

@@ -15,3 +15,5 @@ dist
 /coverage.json
 
 gas_report
+
+*.flat.sol

.prettierignore

@@ -17,3 +17,5 @@ dist
 gas_report
 
 contracts/vendor
+
+*.flat.sol

.solhintignore

@@ -17,3 +17,5 @@ dist
 gas_report
 
 contracts/vendor
+
+*.flat.sol

README.md

@@ -37,11 +37,17 @@ Both alternatives can be migrated to using an API3 feed instead through the Api3
  NETWORK=polygon PROXY_ADDRESS=0x98643CB1BDA4060d8BD2dc19bceB0acF6F03ae17 yarn deploy-deterministically
  ```
 
- You can also just print the expected address after deployment.
+You can also just print the expected address after deployment.
 
- ```sh
- PROXY_ADDRESS=0x98643CB1BDA4060d8BD2dc19bceB0acF6F03ae17 yarn print-deterministic-deployment-address
- ```
+```sh
+PROXY_ADDRESS=0x98643CB1BDA4060d8BD2dc19bceB0acF6F03ae17 yarn print-deterministic-deployment-address
+```
+
+You can flatten the contract to verify it on a block explorer.
+
+```sh
+yarn flatten
+```
 
 ## Differences between API3 and Chainlink feed interfaces
 

package.json

@@ -23,6 +23,7 @@
  "scripts": {
  "build": "hardhat compile && tsc -p tsconfig.build.json",
  "deploy-deterministically": "hardhat run scripts/deploy-deterministically.ts --network $NETWORK",
+ "flatten": "hardhat flatten contracts/Api3ProxyToAggregatorV2V3Interface.sol > Api3ProxyToAggregatorV2V3Interface.flat.sol",
  "lint": "yarn prettier:check && yarn lint:eslint && yarn lint:solhint",
  "lint:eslint": "eslint . --ext .js,.ts",
  "lint:solhint": "solhint ./contracts/**/*.sol",