add dependabot.yml

[shizunge]

No description provided.

[axllent]

Thank you.

1. I don't believe the docker config has any purpose as the Dockerfile uses both the golang:alpine & alpine:latest images which is always the most current. Can you please confirm your logic for adding it?
2. I think it would be far more useful to include npm within that:

  - package-ecosystem: "npm"
    directory: "/"
    schedule:
      interval: "weekly"

Is there any reason you did not include npm? If not, then please could you add it, thank you?

[shizunge]

1. It is a precaution to include Dockerfile.
2. Done.

[axllent]

Thank you - this has been merged 👍