new: can choose between devnet and testnet

.env.example

@@ -1 +1,2 @@
+NETWORK=testnet
 ADDRESS=WALLET1,WALLET2

README.md

@@ -13,9 +13,12 @@ Copy the `.env.example` file and rename it to `.env`. Fill the variables with yo
 Don't forget to put `,` between the wallets.
 
 ```env
-WALLET=wallet1,wallet2,etc
+NETWORK={network}
+WALLET={wallet1},{wallet2},{wallet3},...
 ```
 
+NETWORK can be `devnet` or `testnet`.
+
 ## Run
 
 ### Run with go

main.go

@@ -29,7 +29,7 @@ func main() {
 
 func run(w string) {
 	for {
-		url := "https://faucet.devnet.sui.io/gas"
+		url := "https://faucet." + strings.ToLower(os.Getenv("NETWORK")) + ".sui.io/gas"
 
 		request := `
 			{"FixedAmountRequest":{"recipient":"` + w + `"}}