update readme for incremental

README.md

@@ -1,17 +1,26 @@
 # payload dumper
-Script work with Nokia 7 plus
+Script tested on Yandex Amber OTA's (full and incremental) under Linux(but may works on Windows too)
 
-### System requirement
+## System requirement
 
 - Python3, pip
 - google protobuf for python `pip install protobuf`
 
-### Guide
+## Guide
 
 - Make you sure you have Python 3.6 installed.
-- Download payload_dumper.py and update_metadata_pb2.py here.
+- Download payload_dumper.py and update_metadata_pb2.py
 - Extract your OTA zip and place payload.bin in the same folder as these files.
 - Open PowerShell, Command Prompt, or Terminal depending on your OS.
 - Enter the following command: python -m pip install protobuf
+
+### Full OTA
+
 - When that’s finished, enter this command: python payload_dumper.py payload.bin
-- This will start to extract the images within the payload.bin file to the current folder you are in.
+- This will start to extract the images within the payload.bin file to the out folder you are in.
+
+### Incremental OTA
+
+- Copy original images (from full OTA or dumped from devices) to old dir (with part name + .img, ex: boot.img, system.img)
+- run python payload_dumper.py --diff payload.bin
+- file extracted to the out folder you are in.