GITBOOK-529: support vtt in hls

Author: getroot

docs/subtitles/README.md

@@ -7,7 +7,7 @@ From OvenMediaEngine 0.19.1 and later, you can insert subtitles into live stream
 <figure><img src="../.gitbook/assets/image (1) (1).png" alt=""><figcaption></figcaption></figure>
 
 {% hint style="info" %}
-Currently, only the LL-HLS publisher is supported. HLS and WebRTC will be supported in future releases.
+Currently, the LL-HLS and HLS publishers are supported. WebRTC will be supported in future releases.
 {% endhint %}
 
 To enable subtitles, add a `subtitles` section under  `<Application><OutputProfiles><MediaOptions>` as follows: