Create Kokoro TTS JavaScript library (#3)

* Set up JS project

* Finalise JS library

* Update README

* Fix package.json repository url

* Rename package -> `kokoro-js`

* Fix samples in README

* Cleanup README

* Bump `phonemizer` version

* Create web demo

* Run prettier

* Link to model used in demo

* Enable multithreading in HF space demo (~40% faster)

* Add link to demo in README

* Bump to v1.0.1

kokoro.js/demo/src/worker.js

@@ -0,0 +1,20 @@
+import { KokoroTTS } from "kokoro-js";
+
+const model_id = "onnx-community/Kokoro-82M-ONNX";
+const tts = await KokoroTTS.from_pretrained(model_id, {
+  dtype: "q8", // Options: "fp32", "fp16", "q8", "q4", "q4f16"
+});
+
+self.postMessage({ status: "ready" });
+
+// Listen for messages from the main thread
+self.addEventListener("message", async (e) => {
+  const { text, voice } = e.data;
+
+  // Generate speech
+  const audio = await tts.generate(text, { voice });
+
+  // Send the audio file back to the main thread
+  const blob = audio.toBlob();
+  self.postMessage({ status: "complete", audio: URL.createObjectURL(blob), text });
+});