Updated Logging and error handling (markdown)

Logging-and-error-handling.md

@@ -24,9 +24,14 @@ Note that to keep the call stack information intact, all calls to these methods
 
 
 ## Contents
+- [[TL;DR (a.k.a. sample codes)]]
 - [[Architecture]]
-- [[Setting up]]
-- [[Saving and processing transactions]]
-- [[Fetching and querying]]
-- [[Logging and error handling]]
-- [[Observing changes and notifications]]
+- CoreStore Tutorials
+    - [[Setting up]]
+    - [[Migrations]]
+    - [[Saving and processing transactions]]
+    - [[Fetching and querying]]
+    - [[Logging and error handling]]
+    - [[Observing changes and notifications]]
+- [[Installation]]
+- [[Changesets]]