DOCS-841 change from [] to <> for variable portions

Author: Ed Costello

source/reference/command/collMod.txt

@@ -15,10 +15,10 @@ collMod
 
    .. code-block:: javascript
 
-      db.runCommand( {"collMod" : [collection] , "[flag]" : [value] } )
+      db.runCommand( {"collMod" : <collection> , "<flag>" : <value> } )
 
-   In this command substitute ``[collection]`` with the name of a
-   collection in the current database, and ``[flag]`` and ``[value]``
+   In this command substitute ``<collection>`` with the name of a
+   collection in the current database, and ``<flag>`` and ``<value>``
    with the flag and value you want to set.
 
    .. index:: document; space allocation