Syntax for <mark> tag

[kizu]

This tag mostly should be used inside code blocks, and as the default markdown behavior is to escape everything inside code blocks, it's rather problematic to mark things there.

What we need is to find out how to mark things up inside code in a way it could be then marked with the <mark> tag, with all the classes attached to it if any.

The best way is to find out a syntax that would have assymetric symbols in it, like ~=markedsmth=~ — such constructs are easier to parse. This combinations should be unique enough, so they won't be there in 99.9% of code people would use in their slides.

[kizu]

Right now it's just the <mark></mark> tag with two variants (<mark class="comment"> and <mark class="important">) supported, so they're just unescaped after markdown rendering. But they're ugly and it's hard to attach any other classes to them.

[kizu]

I think the best way would be to use constructs like this:

• __**something**__ for <mark>something</mark>
• __**!something**__ for <mark class="important">something</mark>
• __**//something**__ for <mark class="comment">something</mark>
• __**->something**__ for <mark class="next">something</mark>

This would be unique enough combination of symbols and kramdown won't render nested <strong>s, so we could use those both for generated html and inside code blocks, with both !////-> etc. variants.