[DOC] Openid Additional Parameters Feature is not documented

[HenryTheSir]

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.
Feature implemented in: opensearch-project/security-dashboards-plugin#1637 is currently not documented anywhere in the docs for openid
Version: List the OpenSearch version to which this issue applies, e.g. 2.14, 2.12--2.14, or all.
2.19, 3.x
What other resources are available? Provide links to related issues, POCs, steps for testing, etc.
There was a merged PR but was reverted:

#5600

Maybe we can redo the documentation for this nice feature 🥳

[natebower]

@HenryTheSir Would the reverted PR address this issue?

[HenryTheSir]

I think reverting the revert would solve the issue.

[natebower]

@HenryTheSir I reverted the revert here and also made some edits to the text here, and everything looks fine to me in VSC, but I'm still not seeing it on the website. It looks like the original PR was merged in 2023 and had multiple reverts afterwards. Any ideas?

[natebower]

@HenryTheSir Requested information now displaying. Thanks!