Fix: 404 error on signin/signup links of the Wiki Authentication page

[minhnimble]

Issue

The Sign up endpoint and Sign in endpoint on the Authentication page is showing 404 error at the moment.

As a result, the candidate couldn't follow the instructions to create their own account to test the API properly.

Expected

The signup and signin endpoints should be updated to match with the new postman collections:

• Signin: https://documenter.getpostman.com/view/11835486/UVsPNPfU#deb6f64d-60a4-434b-9c83-215ad8a07568
• Signup: https://documenter.getpostman.com/view/11835486/UVsPNPfU#cb4e8aa7-c54c-4973-82b6-7b8783d9d719

Steps to reproduce

1. Go to Wiki -> Authentication page:
2. Click on the Sign up endpoint or the Sign in endpoint
3. Observe the result

[hoangmirs]

Fixed: https://github.com/nimblehq/nimble-survey-web/wiki/Authentication @minhnimble Could you help verify it and close this issue 🙏