added Making a Heap Allocator

Author: rby90

README.md

@@ -80,6 +80,7 @@ A list of C tutorials that work through the creation of small and or large proje
 * [Hack the Virtual Memory](https://blog.holbertonschool.com/hack-virtual-memory-stack-registers-assembly-code/)
 * [Emulator 101](http://emulator101.com/)
 * [How to Program a Text Adventure in C](https://helderman.github.io/htpataic/htpataic01.html) [In-progress]
+* [Making a Heap Allocator](https://handmade.network/wiki/2877-tutorial_making_a_heap_allocator)
 
 ## Videos