Adjust pipeline-config to match [Terminology](https://woodpecker-ci.org/docs/next/usage/terminology)
based on https://framadate.org/jVSQHwIGfJYy82IL close #1793
Dropped support for `DRONE_*` environment variables in pipeline steps. Pipeline meta-data can be accessed with `CI_*` variables. - `CI_*` prefix replaces `DRONE_*` - `CI` value is now `woodpecker` - `DRONE=true` has been removed
* Refactor: move cncd/pipeline/ to pipeline/ * Refactor: move pipeline/pipeline/ to pipeline/