Add jstrieb/sytems-programming-cheat-sheet (#5423)

* Add jstrieb/sytems-programming-cheat-sheet

* Swap alphabetical order ("the" matters)

more/free-programming-cheatsheets.md

@@ -35,6 +35,7 @@
 ### C
 
 * [C Reference Card (ANSI)](https://users.ece.utexas.edu/~adnan/c-refcard.pdf) (PDF)
+* [Systems Programming Cheat Sheet](https://github.com/jstrieb/systems-programming-cheat-sheet)
 * [The C Cheat Sheet: An Introduction to Programming in C](https://sites.ualberta.ca/~ygu/courses/geoph624/codes/C.CheatSheet.pdf) - Andrew Sterian (PDF)