mod_ssml: add default config for interpret-as='characters'

conf/rayo/autoload_configs/ssml.conf.xml

@@ -21,6 +21,7 @@
 	<!-- map interpret-as to say macros -->
 	<macros>
 		<macro name="cardinal" method="pronounced" type="number"/>
+		<macro name="characters" method="pronounced" type="name_spelled"/>
 	</macros>
 
 </configuration>

src/mod/formats/mod_ssml/conf/autoload_configs/ssml.conf.xml

@@ -21,6 +21,7 @@
 	<!-- map interpret-as to say macros -->
 	<macros>
 		<macro name="cardinal" method="pronounced" type="number"/>
+		<macro name="characters" method="pronounced" type="name_spelled"/>
 	</macros>
 
 </configuration>