// release-note files under docFS. It checks that the files exist and that they have
// some minimal content (see [CheckFragment]).
// The docRoot argument is the path from the repo or project root to the root of docFS.
// It is used only for error messages.
func CheckAPIFile(apiFS fs.FS, filename string, docFS fs.FS, docRoot string) error {
	features, err := parseAPIFile(apiFS, filename)
	if err != nil {
		return err
	}