[DOC] missing documentation on discovery & cluster formation

[rursprung]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request and all versions that are affected.

OpenSearch is missing equivalent documentation on the Elasticsearch documentation on discovery and cluster formation. Especially important would be the information on quorum-based decision making and voting configuration (with the recommendations on settings).

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.

• the old Elasticsearch documentation (while OpenSearch still behaves the same as ES 7.10 in these regards), see the links above.
• there is some very limited documentation on creating a cluster in the OpenSearch documentation