add text highlight for markdown

[huangziwei]

Hello,

I know that text highlight (==text==) is not part of standard markdown, but it would be nice to support it. My current workaround is just to use html mark tag (<mark>text</mark>) but it's cumbersome...

[kmaasrud]

Going forward, mdzk's most important feature will not be converting Markdown to HTML, but rather producing a graph from you Zettelkasten that can be used for whatever you want with any other tool. As previously stated, we will include an optional SSG, in which we might consider including highlight support, but this is quite far down the road.

Hopefully, the <mark>-method works okay for you while we are working towards mdzk 1.0 😄 I will leave this issue open, but put it on the backburner for now.