fix(docs): document how to copy migration history to new project (supabase#20508)

fix: document how to copy migration history to new project

Author: sweatybridge

apps/docs/pages/guides/platform/migrating-and-upgrading-projects.mdx

@@ -153,6 +153,7 @@ Note that this direct connection string to the database uses IPv6. If your netwo
 supabase db dump --db-url "$OLD_DB_URL" -f roles.sql --role-only
 supabase db dump --db-url "$OLD_DB_URL" -f schema.sql
 supabase db dump --db-url "$OLD_DB_URL" -f data.sql --use-copy --data-only
+supabase db dump --db-url "$OLD_DB_URL" -f history.sql --use-copy --data-only --schema supabase_migrations
 ```
 
 ### Restore to your new project
@@ -186,6 +187,7 @@ psql \
  --file schema.sql \
  --command 'SET session_replication_role = replica' \
  --file data.sql \
+ --file history.sql \
  --dbname "$NEW_DB_URL"
 ```