Update README.md

Joseph Luce · web-flow · commit dd9a92e3cf16 · 2018-08-21T23:40:27.000-07:00
diff --git a/system_design/README.md b/system_design/README.md
@@ -3,3 +3,6 @@
 
 ### How would you design a messenger app?
 - https://www.youtube.com/watch?v=5m0L0k8ZtEs
+
+### Rest Api and HTTP
+- https://www.youtube.com/watch?v=rhTkRK53XdQ
