add list syntax example in for powershell

powershell.html.markdown

@@ -68,6 +68,7 @@ $aString="Some string"
 # Or like this:
 $aNumber = 5 -as [double]
 $aList = 1,2,3,4,5
+$anEmptyList = @()
 $aString = $aList -join '--' # yes, -split exists also
 $aHashtable = @{name1='val1'; name2='val2'}