update learning resources

content/posts/Learning-Resources.md

@@ -50,5 +50,6 @@ I found many platforms that teach crypto but none was purely theorical nor solel
 
 - [hackpack](https://hackpack.club/): ok this one is not just into theory but I thought it deserved to be here
 - [ctf resources](https://ctfs.github.io/resources/): more resources
+- [Erling Ellngsen's website](http://alf.nu/)
 
 That's mostly what I got so far. I am still looking for more learning resources and I will add them here when I find more. You can contact me anytime if you have any interresting one to share. You can check my other articles to get more "practical" learning resources.