Add WebAssembly example for VAD + Moonshine models.

[csukuangfj]

You can try it in the following huggingface space:

https://huggingface.co/spaces/k2-fsa/web-assembly-vad-asr-sherpa-onnx-en-moonshine-tiny

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You can download files for the above huggingface space and run them locally by visiting:
https://github.com/k2-fsa/sherpa-onnx/releases/tag/v1.10.30

The following is an example:

wget https://github.com/k2-fsa/sherpa-onnx/releases/download/v1.10.30/sherpa-onnx-wasm-simd-1.10.30-vad-asr-en-moonshine_tiny.tar.bz2

tar xvf sherpa-onnx-wasm-simd-1.10.30-vad-asr-en-moonshine_tiny.tar.bz2
cd sherpa-onnx-wasm-simd-1.10.30-vad-asr-en-moonshine_tiny
python3 -m http.server 6006

# Now open your browser and visit http://localhost:6006/

You should see something like the following: