Update README.md

Author: alesanchezr

exercises/02-Hello-World/README.md

@@ -1,3 +1,7 @@
+---
+tutorial: https://www.youtube.com/watch?v=miBzmGgMIbU
+---
+
 # `02` Hello World
 
 In JavaScript, we use `console.log` to make the computer write anything we want (the content of a variable, a given string, etc.) in something called `the console`.
@@ -16,4 +20,4 @@ Use console.log to print "Hello World" on the console. Feel free to try other th
 ## 💡 Hint:
 
 5 minutes video about the console:
-https://www.youtube.com/watch?v=1RlkftxAo-M
+https://www.youtube.com/watch?v=1RlkftxAo-M