Gear be/fdr 52 be docs gateway checkin

[macgeargear]

Change made

•  New features
•  Bug fixes
•  Breaking changes
• Refactor

Describe what you have done

• create API docs for /api/v1/checkin
• POST: /api/v1/checkin
• user_id have to be real user_id created from user service, otherwise it will not create

• GET: /api/v1/checkin/email/:email

• GET: /api/v1/checkin/:userId

New Features

Fix

• fix POST /api/v1/checkin/create to POST /api/v1/checkin
• fix ProtoDtos return nil to [] if there're no content

Others

[macgeargear]

You might see that there are many duplicate records in which user_id, email, and event are the same value, it will be fixed after @JJnvn fixes his pr in checkin services