Define the process to bring upstream changes

[AlexRuiz7]

Description

To keep this repository up-to-date with the original OpenSearch Repository, we need to periodically sync the fork bringing here (fork) the new changes made in the original repository (upstream).

For that, we'll follow the strategy defined in this article. To minimize the conflicts between the repos, we'll use the rebase strategy, replaying our work on top of OpenSearch Dashboards features.

We want to sync the fork once a week at least, so we'll also need to automatize this process. For that, we'll use GitHub Actions, and this action in particular.

[AlexRuiz7]

We'll add this action, however, we'll see if it's possible to bring this, and other actions, to the Wazuh organization, so we can have control over the source code.