upd readme

Author: sobolev-igor

README.md

@@ -7,7 +7,7 @@
 [![Discord](https://badgen.net/badge/zerion/Zerion?icon=discord&label=discord)](https://go.zerion.io/discord)
 [![Twitter Follow](https://badgen.net/twitter/follow/zerion_io?icon=twitter)](https://twitter.com/intent/follow?screen_name=zerion_io)
 
-**DeFi SDK** is an open-source system of smart contracts allows you to execute trades with ERC20 tokens and track balances on different protocols.
+**DeFi SDK** is an open-source system of smart contracts that allows you to execute trades with ERC20 tokens and track balances on different protocols.
 
 If you have any questions about DeFi SDK, feel free to reach out to us on our [Discord server](https://go.zerion.io/discord).