Fix page paths

Update PostListPageGenerator.swift

CHDataManagement/Generator/Post Lists/FeedGeneratorSource.swift

@@ -23,7 +23,14 @@ struct FeedGeneratorSource: PostListPageGeneratorSource {
         content.settings.localized(in: language).description
     }
 
+    /**
+     The url to the page, including a leading slash
+     */
     func pageUrlPrefix(for language: ContentLanguage) -> String {
-        content.settings.localized(in: language).feedUrlPrefix
+        let prefix = content.settings.localized(in: language).feedUrlPrefix
+        if prefix.hasPrefix( "/" ) {
+            return prefix
+        }
+        return "/" + prefix
     }
 }