Thank you for posting your query on Microsoft Q&A, from above description I could understand that you are looking for advisory on creating a support documentation for your SSO application to be published in the gallery.
PFB answers inline:
- What is the list of supported identity providers? Can i provide "Microsoft Azure Active Directory (AD)" ? Yes, you need to mention Entra ID and also list if there other identity providers that support the application with links to setup those IDP. Example : https://aws.amazon.com/blogs/modernizing-with-aws/integrate-multiple-microsoft-entra-id-tenants-with-aws-iam-identity-center/
- Licensing information -> Please give me an example of what kind of license is required? Mention what subscription or suite is needed to access the application. This is supposed to be shared in Prerequisites
- Troubleshooting Information: Most of our partners have their own documentation or update generic issues as known issues.
- Support mechanisms for users? What should a business user do if the provisioning does not work even after following troubleshooting guide. Any support or community contact information must be updated and active.
- When creating documentation, what file extension that it need, e.g. docx? Since these steps are for your application documentation, it depends on whatever docs hosting vendor you are following as this documentation will be updated on your website and not Microsoft. Kindly following other application examples to add App documentation on the Microsoft site
If you don't have any further queries and the suggestion works as per your business need. Please "Accept the answer (Yes)" and "share your feedback ". This will help us and others in the community as well.
Thanks,
Akshay Kaushik