Fix tagtree.tv link

Fixes facebook#1697.

Author: sophiebits

docs/docs/videos.md

@@ -16,7 +16,7 @@ next: complementary-tools.html
 
 ### Thinking in react - tagtree.tv
 
-A [tagtree.tv](htp://tagtree.tv/) video conveying the principles of [Thinking in React](/react/docs/thinking-in-react.html) while building a simple app
+A [tagtree.tv](http://tagtree.tv/) video conveying the principles of [Thinking in React](/react/docs/thinking-in-react.html) while building a simple app
 <figure>[![](/react/img/docs/thinking-in-react-tagtree.png)](http://tagtree.tv/thinking-in-react)</figure>