[Feature Request] add .vtt format captions

[EbaraKoji]

To play videos with captions on HTML, captions with .vtt format are needed.

MDN WebVTT How to add captions to html video tag

[EbaraKoji]

Subtitles can also be showed with json or srt files, along with customized style.

using videoRef

• parse caption.json file
• get current video time from videoRef.current?.currentTime
• get current caption part
• show its caption

[EbaraKoji]

.vtt caption feature has added.