Mention ethers in one other spot

Author: pcowgill

index.md

@@ -81,7 +81,7 @@ Check out [keythereum](https://github.com/ethereumjs/keythereum) or [ethereumjs-
 
 ### Creating a Dapp?
 
-You will need to interface with the Ethereum network. [web3.js](https://github.com/ethereum/web3.js) provides a complete Javascript API to interact with the RPC interface. If looking for a more lightweight option, [ethereumjs-abi](https://github.com/ethereumjs/ethereumjs-abi) or [ethjs-abi](https://github.com/ethjs/ethjs-abi) can handle the ABI encoding.
+You will need to interface with the Ethereum network. [web3.js](https://github.com/ethereum/web3.js) and [ethers.js](https://github.com/ethers-io/ethers.js) both provide a complete Javascript API to interact with the RPC interface. If looking for a more lightweight option, [ethereumjs-abi](https://github.com/ethereumjs/ethereumjs-abi) or [ethjs-abi](https://github.com/ethjs/ethjs-abi) can handle the ABI encoding.
 
 ### Build for the Web?