Adding doc for new field-type

doc/smarty3-templates.md

@@ -89,7 +89,7 @@ Field parameter:
 3. Help text for the input box,
 4. if set to "required" modern browser will check that this input box is filled when submitting the form,
 5. if set to "autofocus" modern browser will put the cursur into this box once the page is loaded,
-6. if set to "email" or "url" modern browser will check that the filled in value corresponds to an email address or URL.
+6. if set to "email", "url" or "int" modern browser will check that the filled in value corresponds to an email address, URL or numeric.
 
 ### field_intcheckbox.tpl