Upgrading from Wazuh 3.8.2 to 4.3.x with Indexer included is not contemplated in documentation

[alberpilot]

We found a user who had Wazuh 3.8.2. He wanted to upgrade to 4.3 latest including migration to the Wazuh indexer/dashboard.

The following process was: the user goes to the upgrade guide. Click on the Legacy section. Upgrading Wazuh server. (Smooth). Then Upgrading Elastic Stack *. This user concluded that it was necessary to upgrade from 6.6 to 6.8 first and then, jump to 7.x so he used https://documentation.wazuh.com/current/upgrade-guide/legacy/upgrading-elastic-stack/from-6.x-to-6.8.html and then, https://documentation.wazuh.com/current/upgrade-guide/legacy/upgrading-elastic-stack/from-6.8-to-7.x.html. And this last one, upgraded Elastic to Elastic basic to 7.15.2, making impossible the migration to Wazuh indexer.

* On this page, maybe could be useful to describe upgrading strategies and mention the migration.