doc: add import fields

src/routes/apps.js

@@ -547,6 +547,17 @@ async function restore(req, res, next) {
     next(new HttpSuccess(202, { taskId: result.taskId }));
 }
 
+// import has three parts.
+// 1. backupFormat. rsync or tgz
+// 2. remotePath. this is file path
+// 3. backupConfig.provider (see api() function in src/storage.js) differentiates further options
+//      s3 providers - accessKeyId, secretAccessKey, bucket, prefix etc . see s3.js
+//      gcs - bucket, prefix, projectId, credentials . see gcs.js
+//      ext4/xfs/disk (managed providers) - mountOptions (diskPath), prefix, noHardlinks. disk is legacy.
+//      nfs/cifs/sshfs (managed providers) - mountOptions (host/username/password/seal/privateKey etc), prefix, noHardlinks
+//      filesystem - backupFolder, noHardlinks
+//      mountpoint - mountPoint, prefix, noHardlinks
+// 3. backupConfig.password and backupConfig.encryptedFilenames
 async function importApp(req, res, next) {
     assert.strictEqual(typeof req.body, 'object');
     assert.strictEqual(typeof req.app, 'object');