Improvement: Update Permissions of generated workflows to support Private Repos

[Whats-A-MattR]

Minor update / patch to include support for Private Repositories out of the box.

Due to id-token: write being set statically on the generated workflow, other permissions are set / unset to none as outlined in GitHub Action docs.

If you specify the access for any of these scopes, all of those that are not specified are set to none. Source: Github Actions Documentation

I have updated the permissions constant to include contents: read #Required to enable use with Private Repositories The Action should work out of the box now regardless of whether the Repository is Public or Private.