ENH: Add wasi build step

package.json

@@ -7,6 +7,7 @@
     "build": "npm run emscripten && npm run bindgen",
     "emscripten": "npx itk-wasm -b emscripten-build build",
     "bindgen": "npx itk-wasm -b emscripten-build bindgen --output-dir wasm/typescript --package-name mesh-to-poly-data --package-description \"Convert an ITK Mesh to a simple data structure compatible with vtkPolyData.\" --repository 'https://github.com/InsightSoftwareConsortium/ITKMeshToPolyData'",
+    "wasi": "npx itk-wasm -b wasi-build -i itkwasm/wasi build",
     "clean": "git clean -fdx -e node_modules"
   },
   "license": "Apache-2.0",