Update sidebar title for V2 migration guide

Author: tilo-14

references/migration-v1-to-v2.mdx

@@ -1,7 +1,7 @@
 ---
 title: Guide to Migrate Programs from v1 to v2 Merkle trees
 description: V2 reduces CU consumption by up to 70%. V1 remains supported for existing deployments.
-sidebarTitle: Update Guide to V2
+sidebarTitle: V2 Migration Guide
 ---
 
 ## V2 Improvements