start over with nextjs

lib/store.ts

@@ -0,0 +1,14 @@
+const storeDir = process.env.JSON_STORE || '/tmp/pdfer-store/';
+
+import { promisify } from 'util';
+
+import JsonStore from 'json-fs-store'
+
+const store = JsonStore(storeDir);
+
+console.log(`using json-store at ${storeDir}`);
+
+export const list = promisify(store.list);
+export const load = promisify(store.load);
+export const add = promisify(store.add);
+export const remove = promisify(store.remove);