fix types and default placeholder values

lambdas/src/libs/airtable.ts

@@ -25,6 +25,7 @@ export const getAllAirtablePackages = async () : Promise<AirtablePackage[]> => {
         'last_modified',
         'full_name',
       ]),
+      maintainer: record.fields?.maintainer || '',
       desc: record.fields?.description || '',
       thumb_image_url: _.get(record.fields, 'thumb_image[0].url', '/Images/package-thumb-nolabel3.jpg')
     } as AirtablePackage;

lambdas/src/libs/dist_tea_xyz.ts

@@ -1,6 +1,6 @@
 import S3 from 'aws-sdk/clients/s3';
 import { compareVersions, validate } from 'compare-versions';
-
+import _ from 'lodash';
 import type { S3Package } from './types';
 
 const Bucket = process.env.AWS_DIST_BUCKET;