Fix typo

Github -> GitHub

Author: changeworld

README.md

@@ -10,7 +10,7 @@ Contributing to open source is more than just providing updates, it's also about
 
 You've decided to contribute, that's great! To contribute to the documentation, you need a few tools.
 
-#### Github
+#### GitHub
 
 Contributing to the documentation requires a GitHub account. If you don't have an account, follow the instructions for [GitHub account setup](https://learn.microsoft.com/contribute/get-started-setup-github) from our contributor guide.