[css-properties-values-api] Fix indentation in note about transform-list.

Was causing a Bikeshed error message.

Author: jyc

css-properties-values-api/Overview.bs

@@ -352,8 +352,8 @@ The following syntax strings are supported:
 
 :   One of the preceding strings, followed by '+'
 ::  A space-separated list of one or more repetitions of the type specified by the string.
-  Note: Since <transform-list> is already a space separated list, <transform-list>+
-  is invalid.
+	Note: Since <transform-list> is already a space separated list, <transform-list>+
+	is invalid.
 
 :   Any combination of the preceding, separated by '|'
 ::  Any value that matches one of the items in the combination, matched in specified order.