Add Limitations section to the README

README.md

@@ -6,3 +6,9 @@
 $ make
 $ ./heap
 ```
+
+## Limitations
+
+- The pointers to the heap can only be located in the heap and the stack.
+- No packed structs. All of the pointers should be aligned.
+- No tricks that obscure the pointers (like XOR Linked Lists).