fix: Fix typo in sentence about open-source projects

Author: SantanDon

HACKTOBERFEST.md

@@ -1,6 +1,6 @@
 <h1 align="center"> 🎃 HacktoberFest-2022 🎃</h1>
 
-![Opensource](https://img.shields.io/badge/openSource-%E2%9D%A4-blue) ![PR](https://img.shields.io/badge/PRs-welcome-green) ![hacktoberfest](https://img.shields.io/badge/Hacktoberfest-2022-red) ![friendly](https://img.shields.io/badge/beginner-friendly-l)
+![opensource](https://img.shields.io/badge/opensource-%E2%9D%A4-blue) ![PR](https://img.shields.io/badge/PRs-welcome-green) ![hacktoberfest](https://img.shields.io/badge/Hacktoberfest-2022-red) ![friendly](https://img.shields.io/badge/beginner-friendly-l)
 
 # What is HacktoberFest?