Add subtitle format support

[xubmuajkub]

I've made an update so that we can directly get the SRT formatted subtitle.

[AdvMaple]

Can it be read using Aegisub or SubtitleEdit? The json file is formatted so it can't be read by Aegisub. SubtitleEdit can read bilibili json format so I want to download the original json. This can be set as an option in a modal, rather than hard coding.

[xubmuajkub]

Can it be read using Aegisub or SubtitleEdit? The json file is formatted so it can't be read by Aegisub. SubtitleEdit can read bilibili json format so I want to download the original json. This can be set as an option in a modal, rather than hard coding.

@AdvMaple Yes, this can be edited/read by Aegisub. For the other, I haven't tried but it should be fine as I know.

I will create an option for user to select like subtitle if needed.

[AdvMaple]

@xubmuajkub Yes, create a modal so users can choose what type of subtitle to download is preferred. You can group "language" option with "subtitle type" inside the modal.

[xubmuajkub]

@AdvMaple I updated the UI now users can select JSON, SRT, or VTT format as their need.

On download sub button clicked, now resetting the old links before appending new links.

[AdvMaple]

I'll check it out when I back home

[AdvMaple]

Bug: Change language after links have been rendered. File extension become null, set it as json first if extension variable isn't set.

[AdvMaple]

I'm gonna merge this into main branch after I added some fixes and aditional features. In the mean time, I will change the README install link to one of the feature branch. I also want to do some reformat and refactoring.

[xubmuajkub]

Thanks