quintex: add SSH service on boot

Helped debug boot failures in team#41829

provider/quintex.md

@@ -213,7 +213,7 @@ Also create the following `grml.ipxe` file:
 kernel https://dal-rescue.torproject.org/vmlinuz
 initrd https://dal-rescue.torproject.org/initrd.img
 initrd https://dal-rescue.torproject.org/grml.iso /grml.iso
-imgargs vmlinuz initrd=initrd.magic boot=live config fromiso=/grml.iso live-media-path=/live/grml-small-amd64 noprompt noquick noswap console=tty0 console=ttyS1,115200n8
+imgargs vmlinuz initrd=initrd.magic boot=live config fromiso=/grml.iso live-media-path=/live/grml-small-amd64 noprompt noquick noswap console=tty0 console=ttyS1,115200n8 ssh netconfig=http://172.30.131.1/ssh-keys.tgz
 boot
 ```
 
@@ -291,8 +291,14 @@ device:` menu.
 
 Now, when `iPXE initialising devices...` is shown, frantically smash
 the <kbd>ctrl-b</kbd> key combination, because the delay to drop to the
-command-line is too short. You will see `ok` when the initialization
-completes and then the following prompt:
+command-line is too short. 
+
+(Note that it's possible the right image just loads immediately, and
+you don't need to do this whole manual configuration now. The
+following instructions are kept for posterity.)
+
+You will see `ok` when the initialization completes and then the
+following prompt:
 
 ```
 iPXE 1.21.1+ (g4e456) -- Open Source Network Boot Firmware -- https://ipxe.org