Fix #2351: Enhance error documentation with status codes and import paths

[amankp-zop]

Pull Request Template

Description:

• Enhanced the GoFr error handling documentation by adding explicit HTTP status codes to pre-defined error types for improved developer experience.
• Fixes Error documentation enhancement #2351.
• Motivation: Improves clarity by showing the exact status codes (400, 404, 409, 408, 500) returned by GoFr, eliminating the need for developers to reference external documentation or guess appropriate status codes.
• Expected benefit: Better developer experience and quicker debugging.

Breaking Changes (if applicable):

• None – documentation only.

Additional Information:

• No external dependencies beyond existing GoFr modules.
• Testing: No code changes; hence no new tests required.
• Documentation impact: Purely additive, no existing prose or code samples removed.

Checklist:

• I have formatted my code using goimport and golangci-lint (N/A – documentation only).
• All new code is covered by unit tests (N/A – documentation only).
• This PR does not decrease the overall code coverage (N/A – documentation only).
• I have reviewed the code comments and documentation for clarity.
• I have tested the documentation changes locally.
• The changes are consistent with the existing documentation style.
• All HTTP status codes are accurately represented.
• No existing content was removed or modified inappropriately.
• Changes follow the repository's documentation guidelines.

Thank you for your contribution!

[gizmo-rt]

@amankp-zop Seems to be some issue with table rendering

[gizmo-rt]

Visual Ref: https://github.com/amankp-zop/gofr/blob/EN/Error-documentation/docs/advanced-guide/gofr-errors/page.md

[aryanmehrotra]

Syntax is fine, need to be tested by running the dockerfile of the website on local - https://github.com/gofr-dev/gofr/blob/development/docs/Dockerfile
Gofr documentation follows markdoc https://markdoc.dev/