Add openapi / swagger endpoint to the mock server

[lokesh1729]

Describe the feature request
Description of the new feature,

Currently API documentation is present in swagger hub. Why not with the mock server itself? For instance, wiremock by default has this endpoint at http://localhost:8080/__admin/docs/.

The solution you'd like
If you know, describe how you think the feature should be implemented / or should work

Add API docs for mock server