Now the Podcast Episode content type and the first episode node has been
created, serve the new episode from Tome.
It won't appear on the episode listing page at /podcast, but I'll
recreate that once I've migrated the existing episodes to Tome, or I can
manually add it to the listing page by editing the HTML rather than
re-generating the page with Sculpin as it would confuse the commit
history in this project - which I want to keep intact.