update tutorial list in readme; update manifest

Cargo.toml

@@ -4,5 +4,6 @@ members = [
     "part_1_sbot_rocket",
     "part_2_subscribe_form",
     "part_3_database_follows",
-    "part_4_posts_streams"
+    "part_4_posts_streams",
+    "part_5_task_loop"
 ]

README.md

@@ -12,7 +12,11 @@ Author: [@glyph](https://mycelial.technology/)
  - Part 2: Subscription Form and Key Validation
  - Part 3: Database and Follows
  - Part 4: Posts and Message Streams
- - ...
+ - Part 5: Task Loop
+ - Part 6: Display Peers and Update UI
+ - Part 7: Fetch Latest Posts
+ - Part 8: Read, Unread and Delete Posts
+ - Part 9: Extension Ideas and Conclusion
 
 ## Links