lib & config: give shellcheck directions (to /dev/null for dynamic, to repo-relative path for static) for all sourced references

[rpardini]

lib & config: give shellcheck directions (to /dev/null for dynamic, to repo-relative path for static) for all sourced references

• lib & config: give shellcheck directions (to /dev/null for dynamic, to repo-relative path for static) for all sourced references
  • in preparation for tightening the shellcheck severity level
    • it needs to be able to follow all sources; dynamic ones are ignored, static ones need root-relative prefix