refactor: use kirby function to get content folder
refactor: use kirby function to get content folder

closes #16
blankogmbh/kirby-git-commit-and-push-content,blankogmbh/kirby-git-commit-and-push-content,shimikano/kirby-git-commit-and-push-content,shimikano/kirby-git-commit-and-push-content