Add hardware photos to all README files

Hardware Photos Added:
✅ Transmitter image.JPG (5.2 MB) - Actual transmitter hardware photo
✅ Receiver Image.jpg (5.5 MB) - Actual receiver hardware photo

Documentation Updates:
- Main README.md: Added "Hardware Photos" section after system overview
  * Shows actual transmitter unit (battery powered)
  * Shows actual receiver unit (USB powered)
  * Provides visual reference before hardware requirements section

- Transmitter/README.md: Added hardware photo at top
  * Immediately shows users what the transmitter looks like
  * Placed after title, before hardware specifications

- Receiver/README.md: Added hardware photo after architecture
  * Shows complete receiver assembly with OLED display
  * Placed after modular design benefits, before hardware specs

Benefits for Users:
📸 Visual reference of actual hardware
🔧 See component layout and assembly
💡 Understand physical size and connections
✅ Verify their build matches reference design
🎯 Better planning before starting assembly

Image Placement Strategy:
1. Main README: After system diagram, before requirements
2. Transmitter README: Right at top, immediate visual
3. Receiver README: After architecture, before technical details

All images use relative paths (../docs/) for proper rendering in:
- GitHub repository browser
- Markdown editors
- Documentation generators
- Local clones

Total image size: 10.7 MB (high-quality reference photos)

Author: techposts

README.md

@@ -118,6 +118,16 @@ esptool.py --chip esp32c3 --port COM3 --baud 921600 write_flash 0x0 firmware.bin
 └─────────────────────────────────────────────────────────────────────────────┘
 ```
 
+### Hardware Photos
+
+**Transmitter Unit** (Tank Side - Battery Powered):
+
+![Transmitter Hardware](docs/Transmitter%20image.JPG)
+
+**Receiver Unit** (Indoor - USB Powered):
+
+![Receiver Hardware](docs/Receiver%20Image.jpg)
+
 ## 🛠 Hardware Requirements
 
 ### Transmitter (Tank Side)

Receiver/README.md

@@ -23,6 +23,8 @@ Receiver.ino         - Main program loop
 - Better for team collaboration
 - Clearer code organization
 
+![Receiver Hardware](../docs/Receiver%20Image.jpg)
+
 ## Hardware
 
 - **MCU**: ESP32-C3 SuperMini

Transmitter/README.md

@@ -2,6 +2,8 @@
 
 Battery-powered transmitter unit that measures water level using ultrasonic sensor and transmits data via LoRa. Optimized for ultra-low power consumption with deep sleep mode.
 
+![Transmitter Hardware](../docs/Transmitter%20image.JPG)
+
 ## Hardware
 
 - **MCU**: ESP32-C3 SuperMini