Sort channel names

I thought the channel names were already sorted in the source data file,
but it turns out they aren't. I now sort them after sorting the category
names.

src/_data/freetubeCategories.js

@@ -108,10 +108,15 @@ module.exports = async function getSubscriptions() {
     )
   };
 
-  // Categories are sorted alphabetically. Subscriptions are already alphabetized in the incoming data.
+  // Categories are sorted alphabetically.
   const sortedCategories = categories.sort((a, b) => a.name.localeCompare(b.name));
   sortedCategories.push(othersCategory);
 
+  // Subscriptions are sorted alphabetically.
+  sortedCategories.forEach(category => {
+    category.subscriptions.sort((a, b) => a.name.localeCompare(b.name));
+  });
+
   sortedCategories.forEach(category => {
     category.subscriptions?.forEach(channel => channel.tags = subscriptionTags[channel.id])
   });