Update spec/syntax.md

Author: eemeli

spec/syntax.md

@@ -238,6 +238,12 @@ Selector ::= 'match' ( '{' Expression '}' )+
 
 Examples:
 
+```
+match {$count :plural}
+when 1 [One apple]
+when * [{$count} apples]
+```
+
 ```
 let $frac = {$count: number minFractionDigits=2}
 match {$frac}