Generate reference nav to _book.yaml for devsite builds.

<?cs

# print out the yaml nav for the reference docs, only printing the title,

path, and status_text (API level) for each package.

?>

reference:<?cs

each:page = docs.pages?><?cs

  if:page.type == "package"?>

- title: <?cs var:page.label ?>

  path: <?cs var:page.link ?>

  status_text: apilevel-<?cs var:page.apilevel ?><?cs

  /if?><?cs

/each ?>