Update README.md

Author: Joseph Luce

system_design/README.md

@@ -1,14 +1,12 @@
 ### Grokking the System Design Interview
 Start here.
 - https://www.educative.io/collection/5668639101419520/5649050225344512
+- https://github.com/donnemartin/system-design-primer
 
 ### YouTube suggestions
 I recommend checking this guy's channel (Success in Tech). I would actually avoid Tushar Roy's channel, the quality of system design isn't on par. Another possible channel is Gaurav Sen.
 - https://www.youtube.com/channel/UC-vYrOAmtrx9sBzJAf3x_xw
 - https://www.youtube.com/channel/UCRPMAqdtSgd0Ipeef7iFsKw
 
-### Rest Api and HTTP
-- https://www.youtube.com/watch?v=rhTkRK53XdQ
-
 ### Other Resources
 - http://highscalability.com/