Usage questions - remote & branch default values

[laur89]

Not an issue, but some clarifying questions to a new user:

1. Why does remote_name default to deploy as opposed to origin?
2. why does branch default to master as opposed to whatever branch is currently checked out (ie ${DRONE_BRANCH})?
3. ssh_key is mandatory right, ie. there's no way to tap into the authentication granted to drone instance itself?
4. why doesn't remote default to ${DRONE_GIT_SSH_URL}?

This is so the pipeline step definition could be less verbose, assuming the most common use-case would be (commiting and) pushing back to same reporitory & branch.

Following drone step definition works, but feels like it could/should be more terse:

- name: git-push
  image: appleboy/drone-git-push
  settings:
    ssh_key:
      from_secret: github_ssh_key
    branch: "${DRONE_BRANCH}"
    remote: "${DRONE_GIT_SSH_URL}"
    followtags: true
  when:
    branch:
    - master