Preview: https://forgejo.codeberg.page/@docs_pull_998/docs/next/admin/runner-installation/#nixos
Fixes #903.
As described in that issue, the Nix package has been renamed upstream, as well as that the mentioned service module does not exist in reality.
I reworked that section to bring everything up-to-date. The mentioned labels pre-population does not apply to Forgejo, at least. I have also added a small example as reference.
Further, I included a small change to `scripts/preview.sh`, to detect the actual URL open command - on Linux, `xdg-open` is normally the canonical one.
Reviewed-on: https://codeberg.org/forgejo/docs/pulls/998
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Christoph Heiss <christoph@c8h4.io>
Co-committed-by: Christoph Heiss <christoph@c8h4.io>
