Traces updates (#211)

* update traces documentation

* update traces/index.md

Author: DebashisBorgohainO2

docs/user-guide/traces/.pages

@@ -1,3 +1,5 @@
 nav:
 
-- Traces: traces.md
+- Traces Overview: index.md  
+- Traces in OpenObserve: traces.md
+

docs/user-guide/traces/index.md

@@ -1,5 +1,5 @@
 Traces help you understand how requests flow across services, identify performance bottlenecks, and troubleshoot errors in distributed systems.
 
-!!! "Learn more"
+!!! note "Learn more"
     - ### [Traces in OpenObserve](../traces/traces/)