Added example to .Str

Author: Jan-Olof Hendig

doc/Type/Match.pod6

@@ -41,8 +41,15 @@ Alias for L<#method made>.
 
 =head2 method Str
 
+Defined as:
+
+    method Str(Match:D:) returns Str:D
+
 Returns the matched text.
 
+    "abc123def" ~~ /\d+/;
+    say $/.Str;               # 123
+
 =head2 method caps
 
 Returns a list of pairs, with the index or submatch name as key and