Begin to add node-addon-api for sherpa-onnx (#826)

scripts/node-addon-api/lib/sherpa-onnx.js

@@ -0,0 +1,7 @@
+const addon = require('bindings')('sherpa-onnx-node-addon-api-native');
+const streaming_asr = require('./streaming-asr.js');
+
+module.exports = {
+  OnlineRecognizer: streaming_asr.OnlineRecognizer,
+  readWave: addon.readWave,
+}