Improved missing gfycat handling. Added 'preview' marker to index.

src/save/writeToIndex.js

@@ -10,16 +10,24 @@ async function writeToIndex(posts, profilePaths, user) {
     const filename = interpolate(config.library.index.file, user, null, false);
     const now = new Date();
 
-    const newAndUpdatedEntries = posts.concat(user.indexed.updated).map(post => ({
-        id: post.id,
-        subreddit: post.subreddit,
-        permalink: post.permalink,
-        url: post.url,
-        hostId: post.host.id,
-        date: post.datetime,
-        indexed: now,
-        title: post.title,
-    }));
+    const newAndUpdatedEntries = posts.concat(user.indexed.updated).map((post) => {
+        const entryPost = {
+            id: post.id,
+            subreddit: post.subreddit,
+            permalink: post.permalink,
+            url: post.url,
+            hostId: post.host.id,
+            date: post.datetime,
+            indexed: now,
+            title: post.title,
+        };
+
+        if (post.previewFallback) {
+            entryPost.preview = true;
+        }
+
+        return entryPost;
+    });
 
     const data = {
         profile: {