Update link for Glitch: React Starter Kit (#3212)

Remove a trailing slash in link which was causing redirect to a not found page.

content/community/courses.md

@@ -8,7 +8,7 @@ permalink: community/courses.html
 
 ## Free Courses {#free-courses}
 
-- [Glitch: React Starter Kit](https://glitch.com/glimmer/post/react-starter-kit/) - A free, 5-part video course with interactive code examples that will help you learn React.
+- [Glitch: React Starter Kit](https://glitch.com/glimmer/post/react-starter-kit) - A free, 5-part video course with interactive code examples that will help you learn React.
 
 - [Codecademy: React 101](https://www.codecademy.com/learn/react-101) - Codecademy's introductory course for React.