Refactored Swagger UI API and Updated documentation

[ImgyeongLee]

Refactored Swagger UI API and Updated documentation

ASSOCIATED ISSUES:

96

Description

• Now, each endpoint supports rate limiting (10 times per second)
• Erased unnecessary codes
• Fixed bugs about flask-restx usage

✅ INDIVIDUAL_FEATURE: Describe the feature. Lorem ipsum et dolor dolor bil yaul. (Provide explicit instruction on how to test/see this new feature)

NOTE: Please review my PR carefully.

Definition of Done

• [x] Acceptance criteria are validated
• [x] Changes are approved
• [x] Contains no breaking changes
• [x] Changes are implemented in all components
• [x] Each component associated with issue is updated (no stubs)
• [x] Each new feature has unit tests written and confirmed
• [x] All tests pass, no regressions
• [x] All documentation is updated, including release notes