code: function writeJson( row ){
      let targetDir = path.join(dataDir, wofIdToPath(row.id).join(path.sep));
      try {
        fs.ensureDirSync(targetDir);
        fs.writeFileSync( path.join(targetDir, `${row.id}.geojson`), row.body, 'utf8' );
      } catch( error ){
        if( error ){ console.error(`error making directory ${targetDir}`); }
      }
    }
docs: ---------------------------------------------------------------------------- write json to disk