docs: add firmware upload guide and translate platformio.ini comments

- Add FIRMWARE_UPLOAD.md with PlatformIO upload instructions
- Translate platformio.ini comments to English
- Remove redundant comments from platformio.ini

platformio.ini

@@ -0,0 +1,27 @@
+[env:esp32-s3-devkitc-1]
+platform = espressif32
+board = esp32-s3-devkitc-1
+framework = arduino
+monitor_speed = 115200
+upload_speed = 921600
+
+; Partition scheme with LittleFS
+board_build.partitions = default.csv
+board_build.filesystem = littlefs
+
+; Required libraries
+lib_deps = 
+    bblanchon/ArduinoJson@^6.21.3
+    https://github.com/LSatan/SmartRC-CC1101-Driver-Lib.git
+    knolleary/PubSubClient@^2.8
+    links2004/WebSockets@^2.4.1
+
+; Build options
+build_flags = 
+    -DCORE_DEBUG_LEVEL=3
+
+; Serial port (adjust according to your system)
+upload_port = /dev/cu.usbmodem101  ; macOS - ESP32-S3 detected
+monitor_port = /dev/cu.usbmodem101
+; upload_port = COM3                 ; Windows
+; upload_port = /dev/ttyUSB0         ; Linux