Fix an issue for quote

[Cokile]

1. Parser now can parse multiple paragraph correctly.
2. Change the style of quote so it is easy to be distinguished from common
   text.

[Cokile]

Here is the comparison of markdown quote example:

Before：

After：

[Coeur]

Thank you Cokile.

But requirements for TSMarkdownQuoteRegex is to have a space on third line of your example. If you want to make spaces optional, then you should use TSMarkdownShortQuoteRegex.

[Cokile]

@Coeur TSMarkdownShortQuoteRegex works for my example.

Anyway, only for your reference, you should use another font for quote text for a better user experience.