multiline command can easily get ignored/discarded

[teto]

If I configure the following process

  simworker:
    namespace: core
    command:
      source pgtemp.env
      nix run .#simworker

then it's considered as complete but it looks like it does nothing (or possibly just run the first line)

Now if you add a pipe to tell yaml to expect a multiline command and the last line of command is executed correctly

  simworker:
    namespace: core
    # NOTICE THE PIPE
    command: |
      source pgtemp.env
      nix run .#simworker

The current behavior might make sense from a YAML perspective etc but from the user perspective, I feel like a warning could help

[F1bonacc1]

Multiline support is compliant with yaml specifications.
To make things clearer, I added documentation for all the supported variants of multiline commands.