[Portal] Fix: updates broken-links on nebula sessions docs (#6687)

Author: anthonykimani

apps/portal/src/app/nebula/key-concepts/sessions/page.mdx

@@ -5,11 +5,11 @@ Sessions are a way to maintain context across multiple interactions with a user.
 
 - Sessions are created automatically when calling `/chat` without a `session_id` or can be created explicitly by calling the `/session` endpoint.
 - Sessions can be managed through the following endpoints:
-    - [Create Session](/api-reference/create-session)
-    - [Get Session](/api-reference/get-session)
-    - [Clear Session](/api-reference/clear-session)
-    - [Update Session](/api-reference/update-session)
-    - [Delete Session](/api-reference/delete-session)
-    - [List Sessions](/api-reference/list-sessions)
-
-- Sessions persist your conversation history, custom configurations for blockchain data, and thirdweb tools interactions.
+    - [Create Session](/nebula/api-reference/create-session)
+    - [Get Session](/nebula/api-reference/get-session)
+    - [Clear Session](/nebula/api-reference/clear-session)
+    - [Update Session](/nebula/api-reference/update-session)
+    - [Delete Session](/nebula/api-reference/delete-session)
+    - [List Sessions](/nebula/api-reference/list-sessions)
+
+- Sessions persist your conversation history, custom configurations for blockchain data, and thirdweb tools interactions.