ctrlaltdel: add page (#3323)

pages/linux/ctrlaltdel.md

@@ -0,0 +1,15 @@
+# ctrlaltdel
+
+> Utility to control what happens when CTRL+ALT+DEL is pressed.
+
+- Get current setting:
+
+`ctrlaltdel`
+
+- Set CRTL+ALT+DEL to reboot immediately, without any preparation:
+
+`sudo ctrlaltdel hard`
+
+- Set CTRL+ALT+DEL to reboot "normally", giving processes a chance to exit first (send SIGINT to PID1):
+
+`sudo ctrlaltdel soft`