README: Clarify limitations of keypair auth

[edunham]

Summary

I was talking with Noi about auth options in our Terraform module, which are directly inherited from this SDK, and we discovered that the SDK docs weren't clear that certain scopes can only be managed by API keys.

This PR attempts to clarify what keypair auth can be used for. If it should go off and be an issue first instead, please point me in the direction of that process,

Fixes # N/A

Type of PR

• [ ] Bug Fix (non-breaking fixes to existing functionality)
• [ ] New Feature (non-breaking changes that add new functionality)
• [x] Documentation update
• [ ] Test Updates
• [ ] Other (Please describe the type)

Test Information

• [ ] My PR required test updates

Go Version: Os Version: OpenAPI Spec Version:

Signoff

• [ ] I have submitted a CLA for this PR (N/A? I'm an Okta employee in Developer Advocacy, do employees need to do the CLA too?)
• [x] Each commit message explains what the commit does
• [x] I have updated documentation to explain what my PR does
• [ ] My code is covered by tests if required
• [ ] I ran make fmt on my code
• [x] I did not edit any automatically generated files

[MikeMondragon-okta]

Thank you @edunham

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[github-actions[bot]]

This PR has been marked stale because there has been no activity within the last 28 days. To keep this PR active, remove the stale label.

[github-actions[bot]]

This PR has been marked stale because there has been no activity within the last 28 days. To keep this PR active, remove the stale label.

[github-actions[bot]]

This PR has been marked stale because there has been no activity within the last 28 days. To keep this PR active, remove the stale label.

[github-actions[bot]]

This PR has been marked stale because there has been no activity within the last 28 days. To keep this PR active, remove the stale label.