[DOC] Expansion on the 'Security configuration' steps

[leanneeliatra]

What do you want to do?

• [X] Request a change to existing documentation

Tell us about your request.

Clarify the documentation to expand on the steps given. https://opensearch.org/docs/latest/security/configuration/index/

Version: All.

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

[leanneeliatra]

I am actively working on this issue and will submit a PR once ready. Thanks.