Remove newrelic-winston from transport documentation

[kimnetics]

Background

The newrelic-winston transport has become out of date. It uses a deprecated New Relic agent.

Doing an npm install produces the following:

 ✘ npm install newrelic-winston
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: 'newrelic@5.13.1',
npm WARN EBADENGINE   required: { node: '>=6.0.0 <13.0.0', npm: '>=3.0.0' },
npm WARN EBADENGINE   current: { node: 'v18.18.2', npm: '9.8.1' }
npm WARN EBADENGINE }
npm WARN deprecated newrelic@5.13.1: This version of the New Relic Node Agent has reached the end of life.

PR

This PR updates the transports documentation to remove information about newrelic-winston.