Markdown link options {:target=...} not supported

[ysavourel]

In the content

Click [here](https://www.example.com){:target=""blank""} to start.

The {:target="blank"} is extract as text, and not protected.

This additional marker may be an extension, because it seems not to be recognized when i try in on other Markdown editor, like here:

Click here to start.

[Kuro Kurosaka]

Markdown is not a language but a family of languages with a set of common features. Implementing the filter that supports all the Markdown family of languages is impossible because the features of one language often conflicts with another.

This Okapi Markdown filter is designed to support the spec known as Common Mark plus certain extensions found in the Markdown implementation on at github.com (see https://help.github.com/articles/getting-started-with-writing-and-formatting-on-github/).

I don't know what Markdown implementation supports {:target=...} but the Markdown filter is not designed to support such extension. I don't believe Flexmark-Java, the Markdown parser that the Markdown filter uses supports such extension either.