hls.js Fix typo for startFragPrefetch config (#29464)

* Fix typo for startFragPrefetch

* Add startFragPrefetch to test

types/hls.js/hls.js-tests.ts

@@ -23,7 +23,7 @@ class pLoader extends Hls.DefaultConfig.loader {
 
 if (Hls.isSupported()) {
     const video = <HTMLVideoElement> document.getElementById('video');
-    const hls = new Hls({ pLoader });
+    const hls = new Hls({ pLoader, startFragPrefetch: true });
     const version: string = Hls.version;
     hls.loadSource('http://www.streambox.fr/playlists/test_001/stream.m3u8');
     hls.attachMedia(video);

types/hls.js/index.d.ts

@@ -567,7 +567,7 @@ declare namespace Hls {
          * (default: false)
          * Start prefetching start fragment although media not attached yet. Max number of append retries.
          */
-        startFragPrefech: boolean;
+        startFragPrefetch: boolean;
         /**
          * (default: 3)
          * Max number of sourceBuffer.appendBuffer() retry upon error. Such error could happen in loop with UHD streams, when internal buffer is full. (Quota Exceeding Error will be triggered).