feat: enhance podcast feed metadata with season and episode details

- Add `itunesSeason` and `itunesEpisode` fields to podcast feed items for iTunes compatibility.
- Include custom elements `podcast:season` and `podcast:episode` for additional podcast metadata.
- Fix minor formatting issues in `itunesImage` declaration.
- Ensure metadata for transcripts, season, and episode numbers is properly included in the feed.

layouts/podcast.11ty.js

@@ -44,7 +44,7 @@ class PodcastFeed {
       },
       itunesExplicit: data.itunes?.explicit || false,
       itunesCategory: [],
-      itunesImage: data.itunes?.image || data.site.imageUrl || `${data.site.url}${data.page.filePathStem}.jpg`
+      itunesImage: data.itunes?.image || data.site.imageUrl || `${data.site.url}${data.page.filePathStem}.jpg`,
     });
 
     const items = data.collections[data.episodeCollection]?.filter(episode=>episode.data.podcast!=false)
@@ -59,7 +59,9 @@ class PodcastFeed {
         guid: episode.url, // optional - defaults to url
         date: episode.data.date, // any format that js Date can parse.
         enclosure : {url:`${episode.data.podcast.enclosureUrl}`}, // optional enclosure
-        customElements: []
+        customElements: [],
+        itunesSeason: episode.data.season,
+        itunesEpisode: episode.data.episode
         // itunesDuration: duration,
       }
       if (episode.data.podcast.transcriptUrl) {
@@ -69,6 +71,14 @@ class PodcastFeed {
           language:"en-us"
         }}
       })
+      if (episode.data.season && episode.data.episode) {
+        item.customElements.push({ 
+          'podcast:season': episode.data.season,
+      })
+        item.customElements.push({ 
+          'podcast:episode': episode.data.episode,
+      })
+    }
       console.log()
     }
       item = feed.addItem(item);