Add reference to SS64 linux command list

SS64 lists many linux commands and also what they do and how to use them, it is a reference not a tutorial

Author: Scopeuk

src/UsefulLinks.md

@@ -5,3 +5,4 @@
 | Klipper Can Setup | Textual | <https://canbus.esoterical.online/> |
 | Voron Initial Startup Checks | Textual | <https://docs.vorondesign.com/build/startup/> |
 | Git Guide | Textual | <https://glasskube.dev/guides/git/> |
+| SS64 list of linux commands and there use | Textual | <https://ss64.com/bash/> |