[DOC]: documentation changes required for v1

[holashchand]

What is the feature request for?

Registry Core

What problem/inconvenience (if any) will this feature solve?

• id-gen service documentation need to be updated with details about supported formats
• Schema configuration Re-check ie. Private fields not mentioned
• attestation configuration -> mandatory fields
• Tech stack details update
• Bulk issuance api update
• Add roles to bulk configuration
• Add FAQ about 401 in release v1.0.0

Describe the feature clearly.

Add a new feature that does ....