store json after every generate

server/store.js

@@ -0,0 +1,14 @@
+const store = require('json-fs-store')('/tmp/pdfer-store/');
+const { promisify } = require('util');
+
+const list = promisify(store.list);
+const load = promisify(store.load);
+const add = promisify(store.add);
+
+module.exports = {
+    list: () => list(),
+    load: id => load(id),
+    add: item => add(item),
+}
+
+