Fix quickstart.md typo (#500)

Author: distractedm1nd

docs/integrate/quickstart.md

@@ -10,7 +10,7 @@ image: https://matic.network/banners/matic-network-16x9.png
 
 Matic Network is a scaling solution for public blockchains. Matic supports all existing Ethereum tooling along with faster and cheaper transactions.
 
-If you are looking to integrate with Matic Network, you have come to the right place. If you are on of either:
+If you are looking to integrate with Matic Network, you have come to the right place. If you are one of either:
 
 - a blockchain wallet,
 - meta-transaction provider,