docs(OIDC feature): create documentation for native SSO

[ossdhaval]

General Guidelines

• Start by covering the general definition of the feature in a few lines and then point to the appropriate section of the SPEC. Please refrain from repeating what is there in the SPEC already.
• Try to make the content Janssen Server specific ( e.g. what are the related Janssen Server properties or feature flags, how to change relevant settings using TUI/command line (use the screenshots), recommendations around recommended values, use-cases)
• Follow the documentation contribution guidelines.
• Feel free to refer to content available in Gluu documentation (or any other IDP) if the content doesn't need to be customized for Janssen Server

Document Location

https://docs.jans.io/head/admin/auth-server/openid-features/native-sso/

Suggested sections

Relevant Gluu documentation for reference: https://gluu.org/docs/gluu-server/4.5/integration/

[ossdhaval]

This issue is to track documentation for #2518