add build script for Windows

build-wasm.cmd

@@ -0,0 +1,40 @@
+@echo off
+setlocal
+
+set "CURR_DIR=%CD%"
+
+set "BUILD_TYPE=%1"
+if "%BUILD_TYPE%"=="" set "BUILD_TYPE=Release"
+
+md build\wasm 2>nul
+if not exist build\emsdk (
+  git clone https://github.com/emscripten-core/emsdk.git build\emsdk
+)
+
+pushd build\emsdk
+rem git pull
+call emsdk.bat install 3.0.0
+call emsdk.bat activate 3.0.0
+call emsdk_env.bat
+popd
+
+pushd build\wasm
+
+call emcmake cmake -DCMAKE_BUILD_TYPE=%BUILD_TYPE% ..\..
+rem Check if Ninja binary exists
+if not exist "ninja.exe" (
+  rem Install Ninja
+  curl -L https://github.com/ninja-build/ninja/releases/download/v1.11.1/ninja-win.zip -o ninja.zip
+  unzip ninja.zip
+  del ninja.zip
+)
+ninja.exe -f build.ninja -j 3
+
+set "TARGET_FILES=QmcLegacy.js QmcWasm.js QmcWasm.wasm QmcWasmBundle.js %CURR_DIR%\LICENSE.txt"
+
+for %%f in (%TARGET_FILES%) do (
+copy "%%f" "%CURR_DIR%\npm"
+)
+popd
+
+endlocal