create windows build script

* Create build.bat

* Update build.bat

* added error handling

* changed error to match build.sh

* update readme to mention windows build script

---------

Co-authored-by: zyriu1 <Suvkq@hotmail.com>
Co-authored-by: p2r3 <41925384+p2r3@users.noreply.github.com>

build.bat

@@ -0,0 +1,28 @@
+@echo off
+setlocal enabledelayedexpansion
+if not exist "%~dp0src\registries.h" (
+    echo Error: 'include/registries.h' is missing.
+    echo Please follow the 'Compilation' section of the README to generate it.
+    pause
+    exit /b 1
+)
+set "files="
+for /f "delims=" %%f in ('dir /b "%~dp0src\*.c" 2^>nul') do (
+    set "files=!files! "%~dp0src%%f""
+)
+if "%files%"=="" (
+    echo No C source files found in "%~dp0src".
+    echo Add .c files to the src folder and try again.
+    pause
+    exit /b 1
+)
+if exist "%~dp0bareiron.exe" del /q "%~dp0bareiron.exe"
+gcc %files% -o "%~dp0bareiron.exe"
+if errorlevel 1 (
+    echo Build failed.
+    pause
+    exit /b 1
+) else (
+    echo Build succeeded: "%~dp0bareiron.exe"
+    pause
+)