update cost docs

Author: aweiteka

docs/command/osdctl_cost.md

@@ -40,7 +40,7 @@ platforms may be added in the future)
 
 * [osdctl](osdctl.md)	 - OSD CLI
 * [osdctl cost create](osdctl_cost_create.md)	 - Create a cost category for the given OU
-* [osdctl cost get](osdctl_cost_get.md)	 - Get total cost of a given OU. If no OU given, then gets total cost of v4 OU.
+* [osdctl cost get](osdctl_cost_get.md)	 - Get total cost of a given OU
 * [osdctl cost list](osdctl_cost_list.md)	 - List the cost of each OU under given OU
 * [osdctl cost reconcile](osdctl_cost_reconcile.md)	 - Checks if there's a cost category for every OU. If an OU is missing a cost category, creates the cost category
 

docs/command/osdctl_cost_get.md

@@ -1,10 +1,10 @@
 ## osdctl cost get
 
-Get total cost of a given OU. If no OU given, then gets total cost of v4 OU.
+Get total cost of a given OU
 
 ### Synopsis
 
-Get total cost of a given OU. If no OU given, then gets total cost of v4 OU.
+Get total cost of a given OU
 
 ```
 osdctl cost get [flags]
@@ -17,7 +17,7 @@ osdctl cost get [flags]
   -h, --help          help for get
       --ou string     get OU ID
   -r, --recursive     recurse through OUs
-  -t, --time string   set time
+  -t, --time string   set time. One of 'LM', 'MTD', 'TYD', '3M', '6M', '1Y'
 ```
 
 ### Options inherited from parent commands

docs/command/osdctl_cost_list.md

@@ -16,7 +16,7 @@ osdctl cost list [flags]
       --csv           output result as csv
   -h, --help          help for list
       --ou string     get OU ID
-  -t, --time string   set time
+  -t, --time string   set time. One of 'LM', 'MTD', 'TYD', '3M', '6M', '1Y'
 ```
 
 ### Options inherited from parent commands