[BUG] VTT Format invalid

[mutschler]

Description

The Generated vtt file is not compatible with W3C Spec of webvtt.

To Reproduce

Steps to reproduce the behavior:

1. Download webvtt file
2. Open File

Currently the file is created like this:

WEBVTT

1
00:00:00,820 --> 00:00:04,799
- Here goes the Text

Should be according to https://w3c.github.io/webvtt/

WEBVTT

1
00:00:00.820 --> 00:00:04.799
Here goes the Text

Any reason why the time is seperated by , instead of . for milliseconds and every line is prefixed by - ?
Afaik the hyphen is only used to tell the player that there should be a new line. and can be discarded if there is no manual line breaks

From reading the Specs basic WebVTT is basically what you already provide by srt with WEBVTT followed by a empty line added at the top.

[pluja]

this should be fixed in the latest release