Adding environment setup and instructions

flash.bat

@@ -0,0 +1,22 @@
+@echo off
+REM =============================================
+REM Flash ESP32 using Python script + settings.json
+REM =============================================
+
+REM Check for venv
+IF NOT EXIST .venv\Scripts\python.exe (
+    echo [ERROR] Python virtual environment not found at .venv\
+    echo Run setup-env.bat first.
+    pause
+    exit /b 1
+)
+
+REM Activate venv and run flash.py
+call .venv\Scripts\activate.bat
+
+echo [INFO] Flashing firmware using flash.py and settings.json...
+python flash_tool\flash.py
+
+REM Pause to view output
+echo.
+pause