doc: update openapi

[bernard-eugine]

Type of Change

• [ ] Bugfix
• [ ] New feature
• [x] Enhancement
• [ ] Refactoring
• [ ] Dependency updates

Description

Changes made to improve openapi spec readability

Additional Changes

• [ ] This PR modifies the database schema
• [ ] This PR modifies application configuration/environment variables

Motivation and Context

NA

How did you test it?

NA

Checklist

• [x] I formatted the code cargo +nightly fmt --all
• [x] I addressed lints thrown by cargo clippy
• [x] I reviewed submitted code
• [ ] I added unit tests for my changes where possible
• [ ] I added a CHANGELOG entry if applicable