Document return values for command module

lib/ansible/modules/commands/command.py

@@ -87,6 +87,31 @@ EXAMPLES = '''
   register: myoutput
 '''
 
+RETURN = '''
+cmd:
+  description: the cmd that was run on the remote machine
+  returned: always
+  type: list
+  sample:
+  - echo
+  - hello
+delta:
+  description: cmd end time - cmd start time
+  returned: always
+  type: string
+  sample: '0:00:00.001529'
+end:
+  description: cmd end time
+  returned: always
+  type: string
+  sample: '2017-09-29 22:03:48.084657'
+start:
+  description: cmd start time
+  returned: always
+  type: string
+  sample: '2017-09-29 22:03:48.083128'
+'''
+
 import datetime
 import glob
 import os