Add brief LOCK manual.

doc/README.md

@@ -30,3 +30,4 @@
 - DUMP: [manual](_info_/dump.info), [format](sysdoc/dump.format)
 - DSKDMP: [commands](sysdoc/dskdmp.order)
 - NSALV: [commands](kshack/nsalv.order)
+- LOCK: [commands](_info_/lock.order)

doc/_info_/lock.order

@@ -0,0 +1,25 @@
++       Lock TTY (precede by #)
+-       Unlock TTY (")
+"       Output next character in octal
+_       Type character with ASCII value # (")
+DETACH  Detach job # from its TTY (")
+DOWN    System down in # minutes (")
+DPK     Reinitialize DataPoint Kludge
+FCO     Echo characters in octal, with control, meta bits
+GUN     Kill user with index # (")
+I37     Initialize Model 37 Teletype
+ISPY    Like SPY, but types out in image mode
+NET     Reinitialize ARPANET interface
+O       Echo characters in octal
+P       Return to DDT without killing LOCK
+Q       Return to DDT killing LOCK
+REVIVE  Cancel DOWN command, system will stay up (maybe)
+SPEED   Change Datapoint linespeed (precede by line #)
+SPY     Look at input from TTY (precede by TTY #)
+SYS     Change system checker status
+TEST    Test core job (casual use NOT recommended)
+TGUN    Gun Tourist who has been asked to log out
+TPL     Delete top item on TPL stack
+TVQPY   Change state of TV hardcopy device
+UCLEAR  Initialize microtape directory
+?       List commands