Add option to start new line on silence

[MinmoTech]

Currently subtitle lines are split by the subtitles config options.
I'm using maxLineWidth quite frequently, but this often results in sentences being cut in half.
You can work around this a little by using separatePhrases and by providing a prompt that has punctuation, but it's sadly not reliable enough, especially on long audio.

Therefore I'd like to propose a new option like minPauseDurationForNewLine.
If set to 1, it would start a new line if the next word in the timeline appears 1 second after the current one.

[rotemdan]

Good suggestion. Thanks.

Also, the word, phrase and sentence segmentation will be improved when I switch over to my own text segmentation library, which has been ready for months but not integrated yet (it's possibly one of the best text segmentation libraries available for JavaScript, and in general). Currently the phrase segmentation is very basic and may break phrases between commas used in numbers, like 1,234, the new library will resolve that and other issues.

I'd prefer to add this option along with the transition to the new text segmentation library. I think the subtitle generator can be a good place to start for the transition, since it's not a critical component that could impact important functionality (like alignment).