Clarify description of goal "sign-and-deploy-file"

### New feature, improvement proposal

Currently it just states in https://maven.apache.org/plugins/maven-gpg-plugin/sign-and-deploy-file-mojo.html

> Signs artifacts and deploys the artifacts and signatures in the remote repository.

It should state the API being used for deployment (the POST approach built into Maven Resolver) which is not compatible with all remote repos nowadays. Probably adding a link to https://github.com/maveniverse/njord would be helpful as well.

Start with the sign-and-deploy-file documentation page linked in the issue and compare its current description with the requested clarification. Done means the description identifies the POST approach built into Maven Resolver and links to the Njord project; check the rendered page for accurate wording.

Written by the indexing model from the issue text.