The millenaire/ directory is auto-deployed by Millénaire on each new
version of the mod, erasing all changes made to it.

If you want to customise content, copy the relevant files to the
corresponding location in millenaire-custom/, which is never
touched by updates.

Most files in millenaire-custom/ replace their equivalent in
millenaire/. The following are additive instead:
  - Language files (<culture>_sentences.txt, <culture>_dialogues.txt)
  - Namelists (*.txt under cultures/<culture>/namelists/)
  - Traded goods (traded_goods.json per culture)

See docs/feat/custom-content.md for the full authoring workflow.
