Set up Postman mock server

[bryanwong8]

Is your feature request related to a problem? Please describe.
Set up Postman mock server and routes for Tags and Articles so that frontend devs can start working.

Describe the solution you'd like
Create the CRUD routes and examples for Tag and Article

• CreateTag - /api/tags POST
• UpdateTag - /api/tags/int:tag_id PUT
• DeleteTag - /api/tags/int:tag_id DEL
• FetchTag - /api/tags/int:tag_id GET
• CreateArticle - /api/articles POST
• UpdateArticle - /api/articles/int:article_id PUT
• DeleteArticle - /api/articles/int:article_id DEL
• FetchArticle - /api/articles/int:article_id GET